The White House will renew its effort to draw China into discussions about entering arms control talks, President Biden’s national security adviser said on Friday, and will attempt to establish a global accord that specifies that artificial intelligence programs can never be used to authorize the use of nuclear weapons without a human in the decision loop.

The speech by Jake Sullivan, the adviser, was the first to describe with some specificity Mr. Biden’s plans to deal with a world in which, he said, “cracks in our post-Cold War nuclear foundation are substantial.” But the solutions he pointed to were largely aimed at maintaining nuclear deterrence by supplementing America’s deployed arsenal of 1,550 weapons with new technologies — from precision-strike conventional weapons to technological updates of the existing nuclear complex — rather than entering renewed arms races.

For the first time, Mr. Sullivan was explicit on the American response to China’s rapid military buildup, which the Pentagon says could lead it to deploy up to 1,500 nuclear weapons by 2035, a fivefold increase from the “minimum deterrent” it has possessed for nearly 60 years. If Beijing hits that number, America’s two biggest nuclear adversaries would have a combined force of over 3,000 strategic weapons, which can reach the United States.

But Mr. Sullivan argued that the U.S. arsenal does not need to “outnumber the combined total of our competitors” to remain an effective deterrent.

“It’s important to recognize that when it comes to the issue of the growing nuclear capacity of both Russia and China, that deterrence has to be comprehensive,” Mr. Sullivan said. “We believe in the current context, we have the number and type of capabilities today that we need.”

His efforts to draw China into arms control talks, however, are unlikely to achieve success anytime soon. So far, Chinese officials have refused to even discuss agreements limiting their work on nuclear weapons. And tensions between the United States and China have stayed high after months of rancor and frozen high-level contacts. Though Beijing has returned to the table on some issues, it has struck an even tougher posture on others, complicating the “thaw” in U.S.-China relations that Mr. Biden predicted in May. China has questioned Washington’s sincerity in saying it wants a warmer relationship.

Mr. Sullivan said the administration would attempt to revive arms control discussions among the nuclear-armed members of the United Nations Security Council, which includes China, and push them to embrace agreements on basic issues that can avoid accidental conflict, such as advance notification of missile tests. The United States established such agreements with the Soviet Union and renewed them with Russia, but there is no parallel accord with China.

Mr. Sullivan’s speech, at the annual meeting of the Arms Control Association, a nonpartisan group that advocates nuclear nonproliferation agreements, came at a moment when the nuclear order established during the Cold War has been under more stress than at any point since the 1962 Cuban Missile Crisis.

China’s buildup comes as North Korea has been boasting of major advances in shrinking its nuclear warheads, theoretically enabling it to put them on cruise missiles and other weapons. Mr. Sullivan noted that Iran has built up a large stockpile of near-weapons-grade fuel — a direct result, he charged, of former President Donald J. Trump’s decision to abandon a 2015 accord limiting its nuclear activities.

And Russian officials have been issuing more regular, if usually vague, threats to use tactical nuclear weapons.

“We’re under no illusions that reaching risk reduction and arms control measures will be easy,” Mr. Sullivan said. “But we do believe it is possible.”

Mr. Sullivan said Russia’s decision to suspend provisions of the New START treaty — which expires in early 2026 — and cancel other international pacts had eroded the foundations of arms control efforts.

Russia largely walked away from the New START treaty earlier this year and on Thursday, the United States announced it would take reciprocal action, halting inspections of nuclear sites, no longer providing information on the movement of weapons or launchers and no longer providing telemetry data for ballistic missile tests.

But Mr. Sullivan noted that Russia would continue to adhere to the core of the treaty, limiting its strategic warheads to 1,550. After the treaty expires, both sides will need to decide whether to renew the limits.

Mr. Sullivan said that a fresh arms control effort could begin by expanding notifications of ballistic missile test launches among major nuclear powers. Russia has agreements with the United States and China to notify them of ballistic missile test launches, but there is no such agreement between China and the U.S. Mr. Sullivan said an agreement that China would notify the United States and other permanent members of the Security Council could be possible.

While fairly basic, such a pact could lead to other agreements among the nuclear powers, including on crisis communication channels and restricting the use of artificial intelligence. Mr. Sullivan did not provide many details of the kinds of limits the administration would pursue but said one measure could manage nuclear risk by requiring “a human in the loop for command, control and deployment of nuclear weapons.”

Artificial intelligence is already at play in some missile defense systems, like the Patriot, which can be set to automatically intercept incoming missiles. Increasingly, American policymakers are worried about the temptation among many states to use artificial intelligence in determining whether and how fast to launch nuclear weapons. While that prospect has inspired movie plots for decades, in recent years the real-world challenge has grown more complex.

Artificial intelligence can aid in detecting incoming attacks. But in speeding decision-making, many experts have noted, it can also shorten decision times. The president might discover too late that a warning of incoming attack was based on bad data, faulty sensors or disinformation.

Nevertheless, some countries see some artificial intelligence as a potential deterrent. If a first strike decapitated a country’s leadership, that country’s computers could still carry out a counterattack. President Vladimir V. Putin of Russia often boasts of the Poseidon nuclear-armed torpedo, which can range across the Pacific Ocean even if the Russian leadership has already been wiped out.

“I can’t speak to every context and contingency we have into the future, but as things stand today, we believe that we have what we need,” Mr. Sullivan said.