Last Russia-US treaty on nuclear arms control set to expire

Russia has declared it is no longer bound by limits on the number of nuclear warheads it can deploy, as the last remaining arms control treaty with the United States nears expiry and threatens to dismantle the final constraints on the world’s two largest atomic arsenals.

The comments on Wednesday came as the United Nations called the expiry of the New START treaty a “grave moment for international peace and security”.

The treaty, which was signed in 2010, will expire on Thursday.

The Russian Ministry of Foreign Affairs said that the US had not responded to President Vladimir Putin’s proposal to keep observing the missile and warhead limits in the treaty for another 12 months.

“We assume that the parties to the New START treaty are no longer bound by any obligations or symmetrical declarations within the context of the treaty,” the ministry said.

“Essentially, our ideas are being deliberately ignored. This [US] approach appears mistaken and regrettable,” it said.

New START, which stands for Strategic Arms Reduction Treaty, limits the deployment of strategic nuclear weapons, or those designed to hit an adversary’s key political, military and industrial centers.

Deployed weapons or warheads are those in active service and available for rapid use as opposed to those that are in storage or awaiting dismantlement.

The treaty was a 10-year agreement signed by then-US President Barack Obama and Dmitry Medvedev, a close ally of Putin who served a single term as Russia’s president from 2008 to 2012. It came into effect in 2011.

The treaty was extended in 2021 for five more years after US President Joe Biden took office.

The expiration of the accord means that Moscow and Washington will both be free to increase missile numbers and deploy hundreds more strategic warheads, although this poses logistical challenges and will take time.

US President Donald Trump initially suggested that he was open to the idea of an extension and has often spoken about his desire for nuclear disarmament.

But in January, he brushed off New START’s expiration, telling The New York Times: “If it expires, it expires. We’ll do a better agreement.”

Trump has also called for China to be involved in any future nuclear talks.

Russia and the US’s nuclear arsenal accounts for more than 90 percent of all nuclear weapons in the world.

As of January 2025, Russia had 4,309 nuclear warheads, and the US had 3,700. France and the United Kingdom, who are treaty-bound US allies, have 290 and 225 warheads each, while China has about 600.

Fears of new arms race

Security experts say the end of New START risks fuelling a global arms race that has been unfolding gradually for some time now, including in China.

Miles Pomper, a senior fellow at the James Martin Center for Non-proliferation Studies, said China has tripled its nuclear arsenal over the past decade, while Russia has expanded its short-range weapons following the collapse of the Intermediate Nuclear Forces treaty during Trump’s first term.

“The US has actually not been building up its arsenal,” he told Al Jazeera. “So in a sense, this arms race… has been underway for some time. I don’t think that it will necessarily accelerate rapidly now. But I think the US in particular would like to have the same to be able to match some of the Chinese increases over time,” he said.

As the clock ticked towards the treaty’s expiry on Thursday, Pope Leo urged both sides to not abandon the limits set in the treaty.

“I issue an urgent appeal not to let this instrument lapse,” the first US-born pope said at his weekly audience. “It is more urgent than ever to replace the logic of fear and distrust with a shared ethic, capable of guiding choices toward the common good.”

United Nations ‌Secretary-General Antonio Guterres also called the expiration of the New START treaty a grave moment for international peace and security and urged Moscow and Washington to negotiate a new nuclear arms control framework without delay.

“For the first time in more than half a century, we ⁠face a world without any binding limits on the strategic nuclear arsenals of the Russian Federation and the United States of America – the two States that possess the overwhelming majority of the global stockpile of nuclear weapons,” Guterres said in a statement.

He said the dissolution of decades of achievement in arms control “could not come at a ‌worse time – the risk of a nuclear weapon being used is the highest in decades”.

At the same time, Guterres said there was now an opportunity “to ‌reset and create an arms control regime fit for a rapidly evolving context” and welcomed ‌the appreciation by the leaders of both Russia ⁠and the US of the need to prevent a return to a world of unchecked nuclear proliferation.

“The world now looks to the Russian Federation ‌and the United States to translate words into action,” Guterres said.

“I urge both states to return to the negotiating table without delay and to agree upon a successor framework that restores verifiable limits, reduces risks, and strengthens our common security.”