President Biden plans to cement a newly fortified three-way alliance with Japan and South Korea during a landmark summit at Camp David on Friday, bridging generations of friction between the two Asian powers to forge mutual security arrangements in the face of an increasingly assertive China.

Mr. Biden will host Prime Minister Fumio Kishida of Japan and President Yoon Suk Yeol of South Korea at the presidential retreat in Maryland, the first time he has invited foreign leaders there and the first time the leaders of the three countries will have met in a stand-alone session rather than on the sidelines of larger international gatherings.

While the United States has long been allied with Japan and South Korea individually, historic animosities between Tokyo and Seoul stemming most acutely from Japan’s brutal 35-year occupation of the Korean Peninsula have frustrated American efforts to knit the three into a cohesive partnership. But Mr. Yoon’s recent moves toward rapprochement with Japan have dramatically shifted the dynamics in northeast Asia and Mr. Biden hopes to establish a closer, more enduring alignment.

“What you will see on Friday is a very ambitious set of initiatives that seek to lock in trilateral engagement, both now and into the future,” said Kurt Campbell, the president’s coordinator for Indo-Pacific affairs. “And you will see it across many sectors — in the security realm, in technology and education.”

Biden administration officials said the leaders would sign off on a formal “commitment to consult,” an understanding that the three nations would treat any security threat to one of them as a threat to all of them requiring mutual discussion about how to respond. The pledge would not go as far as the NATO treaty’s Article 5, which obligates allies to “take action” in the event of an attack on any member, but it would reinforce the expectation that the three would act in tandem.

The three will also bolster cooperation on ballistic missile defense, expand annual three-way military exercises and develop a framework for security assistance in Southeast Asia and the Pacific islands. They will also inaugurate the first trilateral hotline so that the leaders can communicate securely in the event of a crisis, according to the officials, who spoke on condition of anonymity to discuss agreements before they are formally announced.

To reinforce the sense of a new era in the relationship, the leaders will also commit to annual meetings between the leaders of the three countries that are intended to continue into future administrations, an institutional arrangement akin to the regular sessions that American presidents have with their Mexican and Canadian counterparts.

But the emerging entente has its limits. Japan was not willing to join a compact that the United States and South Korea agreed to create last spring bringing Seoul into Washington’s strategic planning for the use of nuclear weapons in any conflict with North Korea, according to officials and analysts.

The Nuclear Consultative Group that Mr. Biden and Mr. Yoon decided to form during an April meeting in Washington was intended to coordinate military responses to North Korea, and Washington vowed “to make every effort to consult” with Seoul before using nuclear weapons to retaliate against the North.

Japan, the only country ever to have nuclear weapons used against it, declined to participate, a decision American officials attributed to domestic public sensitivities. “I don’t feel the Japanese government feels that’s necessary or desirable,” said Sheila A. Smith, a Japan specialist at the Council on Foreign Relations.

Still, China has made clear its displeasure about the convergence between the three countries, seeing it as more proof that the United States is plotting to contain its rise.

“The upcoming summit between the leaders of the three countries at Camp David in Maryland later this week aims to form a ‘mini NATO’ structure that will be destructive to regional security, making the situation more complex with more conflicts,” The Global Times, a popular Chinese tabloid controlled by the Communist Party, wrote this week, citing regional experts.

China’s economic dominance in the region makes the shifting partnerships complicated for Japan and South Korea. China is the largest trading partner for each of them. Beijing has already responded harshly to South Korea’s growing ties with the United States; in June, China’s ambassador to Seoul warned that “those who bet on China’s defeat will surely regret it later.”

As the United States and its allies have isolated Moscow, Russia and China have drawn closer and many in the region worry that Beijing may be learning lessons from the Ukraine war in terms of its long-running conflict with Taiwan. Just this week, China’s defense minister, Li Shangfu, visited Moscow and warned against “playing with fire” when it came to Taiwan, saying that any effort to “use Taiwan to contain China” would “surely end in failure.”

No one missed the message sent last month when China and Russia conducted joint military exercises in the Sea of Japan soon after the United States, Japan and South Korea held trilateral missile drills. Nor was it lost on anyone when North Korea welcomed high-level Russian and Chinese delegations for a military parade in Pyongyang one week later.

Still, experts on the region said the three-way accord would not have been possible just a year or two ago, a sign of how much China’s rise has scrambled the equation in the region and how Russia’s invasion of Ukraine has focused thinking about the need for security.

Victor Cha, a vice president for Asia at the Center for Strategic and International Studies and former Asia adviser to President George W. Bush, said the Camp David meeting is “a big deal” that has its origins in the changing threat perceptions in the region.

“This consolidation of the alliance relationships is happening now because the external environment is just so uncertain and unstable,” he said. “There is nothing like an actual, real war, even though it’s in another part of the world, to completely change the way or affect the way leaders think about their own security.”

Mr. Biden has made China a central focus of his foreign policy since taking office, working to stitch together various nations in the region in a sort of latticework of partnerships. He signed a three-way security agreement with Australia and Britain; bolstered the so-called Quad grouping of the United States, India, Australia and Japan; increased the American military presence in the Philippines; and established the Indo-Pacific Economic Framework with 14 nations.

Three of his first four state dinners have honored or will honor leaders from the Indo-Pacific region — Mr. Yoon in April, Prime Minister Narendra Modi of India in June and Prime Minister Anthony Albanese of Australia in October. Mr. Biden also plans next month to visit India, which is hosting the annual meeting of the Group of 20 nations.

A stronger collaboration with Japan and South Korea could be a significant pillar in that strategy. Mr. Yoon, who was elected last year, has sought to resolve old disputes and opened the door for mutual visits with Mr. Kishida.

“China’s entire strategy is based on the premise that America’s number one and two allies in the region can’t get together and get on the same page,” Rahm Emanuel, the American ambassador to Japan, said at a forum at the Brookings Institution along with Mr. Campbell earlier this week. “That’s going to be fundamentally different.” A three-way compact, he said, “will in my view change the strategic landscape of the Indo-Pacific.”

At the same time, American officials took pains to reject comparisons to the North Atlantic Treaty Organization, denying that they are trying to replicate in the Pacific what they called a Cold War-era construct from Europe. NATO’s Article 5 commitment to mutual defense has been invoked only once, when the United States was attacked by terrorists on Sept. 11, 2001.

The “commitment to consult” that will be outlined at Camp David on Friday falls far short of that. It sounds closer to Article 4 of the NATO treaty, under which member nations can bring any security issue to the table for discussion by the alliance’s governing council, although administration officials made clear they do not want to liken it to that either.

On its face, that sounds more bureaucratic than decisive. But experts said it will make the point that the three countries share a strong interest in their mutual security in the face of threats from China, Russia and North Korea.

“I don’t expect it will be an Article 5-type, NATO-type collective defense statement,” said Mr. Cha. “But I think they will get as close as they can to it talking about how the security of the countries are interlinked.”