U.S. officials warn of potential violence at the Sept. 18 rally, but see no ‘specific or credible plot.’

The “Justice for J6” rally, slated for Saturday, is being organized by Matt Braynard, a former Trump campaign operative, and his organization, Look Ahead America. The organization has demanded that the Justice Department drop charges against what the group calls “nonviolent protesters” facing charges stemming from the Jan. 6 riot. Organizers have secured a permit for 700 attendees at the rally, according to the document.

In preparation for the event, security officials have restored a security perimeter around the Capitol including a high fence like the one erected in the wake of the Jan. 6 riot.

The rally is the latest effort to rewrite history of the deadly mob attack on the Capitol, which sought to disrupt Congress’s count to formalize President Biden’s victory in the 2020 election, and which prosecutors say led to as many as 1,000 assaults against police officers. Federal authorities have issued multiple intelligence reports this year warning that the attack on Jan. 6 may not have been an isolated episode, and that domestic extremists have been emboldened by the mob attack and false narratives around the 2020 election.

Mr. Trump put out a statement from his office on Thursday, with no mention of the rally, but saying, “Our hearts and minds are with the people being persecuted so unfairly relating to the January 6th protest concerning the Rigged Presidential Election.” He added: “JUSTICE WILL PREVAIL!”

The latest report, titled “Prospects for Violence at ‘Justice for J6’ Rally in Washington, D.C.,” warns of possible violence both by participants in the rally and by counterprotesters. Those seeking to commit violence could use encrypted communication platforms, making it difficult for law enforcement to disrupt any plans, according to the document.

Still, homeland security officers have found fractured support for the rally among those who have supported the storming of the Capitol on Jan. 6. Some individuals sympathetic to those who breached the Capitol have claimed online that the event is a “‘false flag’ planned by authorities to target potential attendees for arrest and have encouraged like-minded individuals to not attend,” according to the document.

Members of Congress and law enforcement officials have said the security preparations for the rally on Saturday are a stark contrast to the planning in the weeks before Jan. 6. A report by two Senate committees found that authorities failed to adequately warn law enforcement officials and share intelligence before the riot earlier this year.

Unlike the riot of Jan. 6 where the Capitol Police were severely outmanned, the agency plans to be at full staffing for the Sept. 18 rally, and has issued an “emergency declaration” that allows officers from other agencies to be deputized with police powers on Capitol grounds.

On Jan. 6, officers at the Capitol waited for hours to receive help from the D.C. National Guard. But for the Sept. 18 rally, the department has already asked the Defense Department to be ready to send in the National Guard “should the need arise” on Saturday.

In addition to restoring the fence, the Capitol Police has installed new security camera technology to better monitor a wider range of activity around the complex, and has streamlined its intelligence-sharing and planning processes in the wake of the attack.

Congressional leaders have said they are encouraged by briefings they’ve received from the Capitol Police about preparations for Sept. 18.

“I believe that they are well prepared, thorough, professional, and I think they are better prepared than people were before Jan. 6,” Senator Chuck Schumer, Democrat of New York and the majority leader, said after receiving a briefing on the precautions.

In addition to prodding nations to set tough new targets, Mr. Biden will also invite countries to join a global pledge of cutting methane 30 percent by 2030. Methane, which is the main component of natural gas, is the second most powerful greenhouse gas after carbon dioxide.

Environmental advocates said they were optimistic a number of countries would agree to that benchmark, calling it a potentially significant step in curbing climate change. While methane has a shorter lifetime in the atmosphere than carbon dioxide, it is, per unit, more than 20 times as potent at warming the planet.

“Slashing methane emissions is the most important action countries can take to slow global warming in the next few decades,” said Nathaniel Keohane, the president of the Center for Climate and Energy Solutions.

The United States is also likely to face pressure at the forum to boost its funding to help developing countries pivot to cleaner energy and cope with the consequences of climate change. In April, the Biden administration pledged to deliver $5.7 billion annually by 2024.

Jake Schmidt, a senior strategic director for international climate at the Natural Resources Defense Council, an environmental group, noted that the European Union contributed more than $25 billion annually to help the world’s poorer nations address climate change. He called on Mr. Biden to allocate at least $12 billion annually by 2024 ahead of the Glasgow summit.

“The U.S. needs to be bolder on climate finance if we are going to have a chance of success,” Mr. Schmidt said.

Under the Obama administration, the Major Economies Forum typically drew the world’s largest emitters, including the European Union, China, India and Australia, as well as a smattering of other nations that have been pivotal in the global negotiations.

As of late Thursday night, the White House declined to say which countries had accepted Mr. Biden’s invitation.

Vaccination remains powerfully protective against severe illness and hospitalization in the United States in the vast majority of people in all of the studies published so far, experts say. Regulators have said those metrics are key in deciding on whether extra shots are needed now. Vaccines do seem less potent against infection in people of all ages, particularly those exposed to the highly contagious Delta variant.

Committee members seemed particularly interested in whether the data was strong enough to justify additional shots for older Americans but not younger ones. Some expressed concern that the long-term benefit of additional shots remains unclear, and that it is not feasible to repeatedly boost the general population.

The morning’s presentations underscored the complex array of data from disparate sources on whether waning potency of the vaccines might lead to an increase in severe Covid-19 cases among vaccinated people over time. Dr. Sara Oliver, an official with the Centers for Disease Control and Prevention, presented data showing vaccine effectiveness against severe forms of Covid-19 holding strong, even in people 75 and older.

Jonathan Sterne, a professor of medical statistics and epidemiology in the United Kingdom, said he had analyzed 76 different studies on the vaccines’ real world effectiveness, and that multiple factors may have skewed the results.

“You’re making incredibly important policy, policy decisions, very rapidly in a situation of uncertainty,” he said, “and there are very good reasons those decisions have to be made.” But he warned that it was difficult for scientists to reach sound conclusions based on studies of a rapid rollout of vaccines. Those evaluating the case for boosters should be “cautious” of any apparent short-term effects of a booster dose, he said.

Israeli experts told the committee that they believed a third shot of the Pfizer-BioNTech helped dampen a fourth wave of infection due to the Delta variant, which swept the nation this summer. The nation started offering boosters in late July.

Dr. Sharon Alroy-Preis, Israel’s head of public health services, described the rise in the number of hospitalized patients who had been fully vaccinated with two shots of Pfizer’s vaccine as “scary.” After offering boosters to the general population, she said, the nation is now averaging about half as many severe or critically ill patients as the Ministry of Health had anticipated.

Top federal health officials, including Dr. Anthony S. Fauci, President Biden’s chief medical adviser, have argued for weeks that immunity against infection is waning in fully vaccinated people, and that there are hints of diminished protection against more severe forms of Covid-19. Their concern, in other words, is that vaccinated people are becoming more at risk not only of getting asymptomatic or mild cases over time, but of getting sick enough to be hospitalized.

Eight of those officials in August signed a policy statement saying that boosters would be needed and that the administration was prepared to deliver them for adults as early as the week of Sept. 20, a decision some public health experts said was premature.

In its application to the F.D.A., Pfizer is asking for boosters to be given six months after the second dose, not eight months after, as President Biden called for in his booster plan last month.

There has been fierce resistance to boosters from some federal career scientists and many vaccine experts outside the government. Two key F.D.A. regulators wrote in The Lancet this week that there is no evidence additional shots are needed yet for the general population, assessing data from dozens of studies. One of them, Marion Gruber, who directs the F.D.A.’s vaccines office, suggested at the Friday meeting that the evaluation the F.D.A. makes depends on strong clinical studies, and on how boosters doses are performing against currently circulating virus variants, something the agency said in an analysis this week it had little of in Pfizer’s application.

The World Health Organization has asked world leaders to refrain from rolling out boosters at least until the end of the year, with the goal of immunizing 40 percent of the global population first. But some high-income countries have already begun offering boosters to their residents, and others may follow their lead. A number of American scientists have also made the case that more of the world should get initial vaccinations before the United States turns to boosters; even two top vaccine scientists at the F.D.A. did so in the Lancet article, saying there was no credible evidence supporting boosters for the general population yet.

But Dr. Peter Marks, the agency’s top vaccine regulator, warned at the beginning of the meeting Friday against discussing “issues related to global vaccine equity.” Instead, he said, the committee should focus on the scientific questions before them.

The F.D.A. panel — the Vaccines and Related Biological Products Advisory Committee — is composed of independent scientific experts, infectious disease doctors and statisticians, many of whom participated in earlier meetings about coronavirus vaccines.

You can watch the meeting here, which is scheduled to conclude in the late afternoon. A “no” vote on Pfizer’s application could lengthen the discussion and possibly prompt a different vote, such as on whether to recommend clearing the booster for a more limited group.

The Centers for Disease Control and Prevention’s own vaccine advisory panel is set to meet next week, and could make recommendations on how boosters, if cleared by the F.D.A., should be used.

As administration officials argue about the need for the shots, many Americans are taking the matter into their own hands, seeking out booster doses before federal clearance.

However, the White House sent a draft document to summit invitees earlier this week that called for 70 percent of the world’s population to be vaccinated by the time the U.N. gathers again in September of next year.

The United States has already committed to sending more than 600 million doses abroad, and is working to scale up manufacturing overseas, particularly in India.

Mr. Biden has been under fire from global health advocates over his decision to promote booster shots for already vaccinated Americans while much of the world remains entirely unvaccinated and at risk. They want him to work to create manufacturing hubs in many other countries and to press vaccine makers to share their technology as part of a far-reaching plan similar to the one former President George W. Bush created to address the global AIDS epidemic.

The White House officials who discussed Mr. Biden’s summit plan insisted the United States can do both. In an interview earlier this week, Dr. Anthony S. Fauci, Mr. Biden’s top adviser for the coronavirus — and a driving force behind Mr. Bush Emergency Plan for AIDS Relief — said the administration was committed to doing more.

“We’re trying to figure out what is the best way to get a really fully impactful program going,” Dr. Fauci said, noting that building manufacturing plants overseas might be a reasonable step to prepare for any future pandemics, but could not happen quickly enough to end this one. “We want to do more, but we’re trying to figure out what the proper and best approach is.”

Reaching specific global vaccination targets has so far proven difficult. Covax, the U.N.-backed vaccine distribution program, announced this month that it would not be able to meet its forecast for doses available in 2021. So far, only 20 percent of people in poor and middle-income nations have received at least one dose of a Covid vaccine.

Part of the global vaccine shortage stems from potential donor countries’ domestic needs. Some nations in Asia have imposed tariffs and other trade restrictions on Covid vaccines that slowing their delivery overseas. India has banned exports of Covid vaccines, preventing distributions of doses from the Serum Institute of India, the world’s largest vaccine maker.

At a briefing with reporters earlier this week, Loyce Pace, who heads the office of global affairs at the federal Department of Health and Human Services, made particular note of the administration’s work with India to lift the export ban.

“We continue to work with the government of India in particular, on their trajectory of helping produce the world vaccines,” Ms. Pace said.

The sanctions threatened by the order would target individuals and entities from the Ethiopian and Eritrean governments, the Tigray People’s Liberation Front and the Amhara regional government, who face possible asset freezes and travel bans.

They are a step up from weaker and largely ineffectual measures, including visa restrictions, imposed by the United States in May. For now, the new sanctions have yet to be imposed on anyone, and one of the administration officials who provided background declined to give a timeline.

But action would be a matter of “weeks not months,” she said.

To avoid sanctions, leaders on both sides must agree to negotiations without preconditions and accept mediation under the former Nigerian president Olusegun Obasanjo, an African Union envoy who is scheduled to land in Ethiopia this weekend.

But even as American officials scrambled to respond to the French anger, they dismissed the notion of a serious rift. Jen Psaki, the White House press secretary, told reporters that the United States informed the French before the president’s announcement but did not have an obligation to include the country in their arrangement with Australia and Britain.

“This is not the only global engagement or global cooperative partnership the United States has in the world,” she said. She added that the United States and France will continue to be partners in a number of other ways, noting that “the French are a member of the G-7.”

Still, the lack of consultation — and the last-minute revelation — has infuriated French officials in Washington, who on Thursday angrily canceled a gala at their Washington embassy to protest what they called a rash and sudden policy decision that resembled those of former President Donald J. Trump.

Asked what Mr. Biden thinks about being compared to Mr. Trump, Ms. Psaki shot back: “The president doesn’t think about it much.”

The gala was to commemorate the “240th Anniversary of the Battle of the Capes,” celebrating the French navy’s help in a 1781 battle during America’s fight for independence.

Philippe Étienne, the French ambassador to the United States and the host of the party, said on Thursday that he learned about the deal from news reports, followed by a call from Jake Sullivan, the national security adviser to Mr. Biden.

A senior American official said that the Biden administration had made efforts to inform the French government about the president’s announcement earlier Wednesday morning, but had been unable to schedule the discussions with their French counterparts before the news reports appeared online.

The indignation from Mr. Étienne and Mr. Le Drian reflected the fact that France had its own deal with Australia, concluded in 2016, for conventional, less technologically sophisticated submarines. That $66 billion deal is now defunct, but a harsh legal battle over the contract appears inevitable.

“A knife in the back,” Mr. Le Drian said of the Australian decision, noting that Australia was rejecting a deal for a strategic partnership that involved “a lot of technological transfers and a contract for a 50-year period.”

French officials in Washington accused top American officials of hiding information about the deal despite repeated attempts by French diplomats, who suspected that something was in the works, to learn more.

Mr. Étienne, one of France’s most experienced diplomats, acknowledged in an interview on Thursday that there had been discussions with the Australians over the rising price tag of the submarines that France was supposed to deliver to Australia — which were not nuclear-powered, even though France has its own fleet of nuclear-powered submarines.

In early summer, the French government had declined to sign documents committing to the next phase of the deal — apparently because of the pricing disputes. But Mr. Étienne said the deal was about more than just a defense contract.

“We have assets in this region,” he said of France, noting that it has conducted missions in the Pacific, and strategic plans to increase France’s presence. “We take it very seriously.” He added: “It was not only a commercial contract.” He called it “an essential part of our overall Indo-Pacific strategy.”

Ms. Psaki said French “leadership up and down the ranks will continue to be important partners to the United States,” and she suggested that the work of the two countries to seek security in the Pacific would not be compromised because of tensions around the submarine deal with Australia.

“We cooperate closely with France,” she said. “As the President said yesterday, we have a range of shared priorities in the Indo-Pacific, and that will certainly continue. We don’t see this, from our end, as a regional divide.”

Zolan Kanno-Youngs and David E. Sanger contributed reporting.

Gates’s 28-member committee is expected to make its recommendations by mid-November, and the full association could vote on them in January.

The N.C.A.A.’s newfound sense of urgency is not exclusively of its own making. Bombarded by the courts, Congress, state legislatures and even conference commissioners about matters like gender equity and prohibitions on college athletes’ profiting from their fame, the association has been under enormous pressure to make changes that will stave off more legal and political battles that threaten its power.

In an interview with The New York Times, his first with a news organization in his role as the committee’s chairman, Gates acknowledged the difficulty of determining how the N.C.A.A. should function. The constitution that spells out the association’s basic principles and structures runs 43 pages, followed by hundreds of pages of “operating bylaws.”

“There is absolutely nothing anybody can do to alleviate the skepticism toward this endeavor except to make it work, except basically to come forward with something that people recognize as meaningful and significant,” Gates said. “I mean, people’s skepticism is simply based on past history.”