National Security Advisor Jake Sullivan will deliver a speech at the annual National Arms Control Association meeting in Washington outlining the Biden administration's attempt to navigate a rapidly shifting strategic nuclear landscape, senior officials told reporters.

With the last US-Russia arms control treaty -- New START -- largely moribund and due to expire in 2026, Sullivan will say that the United States is keen to forge a new treaty. In the meantime, however, Washington wants for the world's two leading nuclear powers to stick to the core of the treaty -- a limit for each of 1,550 warheads.

"We will discuss the importance of maintaining kind of what we have left of New START," one official said.

"We are willing to maintain those limits if Russia does through the life of the treaty, which expires in February of 2026. Of course, 2026 is not that far away," the official said. "And so we'll also signal that we are open to dialogue, you know, without conditions."

At the core of future arms control will be negotiating with China on its rapidly expanding arsenal and global presence.

"A key variable in all of this is what... our engagement with China (will) look like," another senior official told reporters, speaking on condition of anonymity.

The Biden administration needs to understand China's "willingness to sort of engage in more substantive dialogue with us because the size of their arsenal, the shape of their force, any shift in their policies will impact our own force posture in the future," the official aid.

That "of course will affect our ability to come to some sort of accord with the Russians" -- a reality that will have ripple effects through the other acknowledged nuclear powers, Britain and France.

With relations at rock bottom with President Vladimir Putin's Russia and currently at a near standstill with Beijing, a difficult path lies ahead.

"We have not been able to have this substantive engagement on strategic issues or nuclear issues that we've wanted," an official said, regarding outreach to China. "I think we're hoping that there's more renewed interest in diplomacy to stabilize the relationship now."

In February this year, Putin announced that Russia was suspending participation in New START, a Cold War-era treaty which limits warheads and allows verification by both sides.

The State Department said Thursday that it has made reciprocal "countermeasures" by suspending various aspects of the treaty, including on-site inspections and exchange of data.

Another area Sullivan will address in his speech, officials said, will be "efforts to build norms, rules of the road, responsible behavior" in the AI, space and other high-tech fields.