© Jonathan Ernst/Reuters President Trump with Chinese Vice Premier Liu He at the White House in early April.

The aim of the nascent effort, a senior administration official said, is to bring Russian nuclear weapons unregulated by treaties under new limits and persuade China to join an arms-control pact limiting or verifying its capabilities for the first time.

The initiative is still in its earliest stages, with officials preparing options for how to implement Trump’s order. It is unclear whether it will yield results in an administration that has locked horns with Moscow and Beijing and has less than two years left in its first term.

“The president’s direction is that we need to look at more-ambitious arms control that will deal with more weapons, and more than just us and Russia,” said the senior administration official, speaking on the condition of anonymity to discuss internal policy deliberations. “What you’re going to see is more from the administration on how do we get to arms control that doesn’t just reflect a Cold War mentality.”

A trilateral nuclear arms-control agreement among the United States, Russia and China would be a watershed diplomatic achievement; separate treaties alone would be significant. But normally such pacts require years of negotiation and diplomatic outreach, a challenge for an administration that has withdrawn from arms-control treaties but has not brokered any new ones.

Trump mentioned the goal ahead of trade talks at the White House this month with Chinese Vice Premier Liu He. The president said that Washington, after concluding a trade deal with Beijing, should strike agreements to reduce military spending.

“Between Russia and China and us, we’re all making hundreds of billions of dollars’ worth of weapons, including nuclear, which is ridiculous,” Trump said. “And I would say that China will come along, and I would say Russia will come along. It doesn’t really make sense that we’re doing this.”

The initiative comes as Russia, China and the United States all enhance their nuclear weaponry — and as the clock ticks on the New START accord, the last big arms-control pact remaining between Washington and Moscow, which expires in 2021.

Negotiated by President Barack Obama, the treaty places limits on strategic nuclear platforms such as bombers, submarines and intercontinental ballistic missiles. It can be extended for five years if the presidents of both nations agree.

Secretary of State Mike Pompeo, in testimony before the Senate Foreign Relations Committee on April 10, said Trump has made clear that if the United States can achieve a “good, solid” arms-control agreement with Russia to follow on New START, then Washington should agree. Pompeo said China should be included in the next version of the treaty but signaled how difficult that could be.

“It may be that we can’t get there,” Pompeo said. “It may be we just end up working with the Russians on this.”

This is not the first time that Trump has expressed concern about the costs of an arms race. He said in March 2018 that he wanted to negotiate with Russian President Vladi­mir Putin because it was “getting out of control.” In a December tweet, he said that “at some time in the future” he would hold talks with Putin and Chinese President Xi Jinping about “a meaningful halt to what has become a major and uncontrollable Arms Race.”

The White House is now looking to lay the groundwork for such talks, prompting skepticism among some arms-control advocates who watched with dismay as the president withdrew from a hard-won nuclear accord with Iran and the three-decade-old Intermediate-Range Nuclear Forces Treaty with Russia. The Trump administration cited shortcomings in the Iran agreement and Russia’s violations of the INF Treaty as rationales for pulling out of both pacts.

China has long resisted involvement in arms-control pacts, in part because its suite of nuclear weapons is not as vast as the U.S. or Russian arsenals. Russia has also resisted any limits on its smaller nuclear weapons that fall outside current agreements.

For a commander in chief who prides himself on his negotiating skills, nuclear talks have long appealed to his enthusiasm for dealmaking. In the 1980s, he expressed an interest in negotiating arms-control agreements with the Soviets on behalf of the Reagan administration.

But as president, Trump has surrounded himself with proponents of U.S. unilateralism, including White House national security adviser John Bolton, a disarmament skeptic.

Bolton led the charge to withdraw the United States from the INF Treaty — a pact signed by President Ronald Reagan and Mikhail Gorbachev in 1987 that led to both countries eliminating their ground-launch midrange missiles. Because of the U.S. withdrawal, the treaty will end formally in August. Bolton also took the lead in dismantling the Anti-Ballistic Missile Treaty with Russia during the George W. Bush administration.

Like their predecessors in the Obama administration, officials in the Trump administration have raised concerns about the wide range of small and highly maneuverable nuclear weapons that Russia possesses or is developing — arms the United States lacks in such numbers.

Those weapons, sometimes called tactical or battlefield nuclear weapons, fall outside the parameters of New START and therefore face no regulation. There are also questions about whether New START’s provisions would cover other Russian weaponry under development, including a nuclear torpedo that Putin has touted as impervious to American defenses.

Trump has previously called the New START accord one-sided and would probably prefer to cut his own deal with Moscow rather than extend the pact negotiated by Obama. For months, top U.S. officials have suggested that the administration should pursue an expanded New START that encompasses a wider array of Russian nuclear weapons.

Some disarmament advocates worry that Trump’s more hawkish advisers are floating a broader arms-control discussion with Russia as a way to kill the New START accord. Those advocates express concern that the initiative will set an impossibly high standard for a new agreement, essentially creating a pretext for Trump to walk away from New START when Moscow does not agree to expanded limits.

Daryl Kimball, executive director of the Arms Control Association, said the United States should first extend New START and then move on to bigger ambitions.

“There is simply not enough time, and not enough trust, to negotiate, let alone ratify, a complex, new, legally binding treaty with Russia that addresses these difficult new issues before New START expires in Feb. 2021,” Kimball said in an email. “And if team Trump suggests China must join New START or that Russia must agree to limits on tactical nukes as a condition for its extension, that should be recognized as disingenuous proposals designed to create a pretext for killing New START.”

The Trump administration has not issued any such ultimatums. The senior Trump administration official said disarmament advocates should support the effort to broker agreements with Moscow and Beijing and take a new approach to arms control.

“You can’t have it both ways,” the official said. “You can’t say you are concerned about the nuclear arms race and then criticize the president for trying to stop the arms racing that is being done by Russia and China.”

The worry at the Pentagon is that Russia is developing the suite of smaller, more agile nuclear weapons outside the limits of New START for possible use in a “limited nuclear strike.”

The idea, U.S. officials fear, would be to raise the stakes for the United States by using a small nuclear weapon against an American ally, prompting Washington to rethink whether it is worth coming to the nation’s defense. Russian officials deny they have such a doctrine, which the Pentagon regularly describes as “escalate to de-escalate.”

China — which possesses a full nuclear triad of bombers, submarines and ICBMs as well as an increasingly sophisticated suite of missiles — has refused to negotiate caps on its nuclear program through such arms-control agreements.

In the case of the INF Treaty, even as Russia and the United States were curtailing their production of intermediate-range missiles, China was deploying them in the Pacific.

Trump’s desire to cut arms-control deals is not the only deciding factor in whether the White House-led effort will yield results; the response from Moscow and Beijing will determine whether the initiative amounts to anything.

“We plan to talk to them separately, and we plan to talk to them together,” the senior administration official said. “The United States is not planning to grow significantly its nuclear stockpile. Russia and China cannot say the same thing. We can’t afford to ignore that discussion.”

paul.sonne@washpost.com

john.hudson@washpost.com