Russia says it regrets end of landmark nuclear treaty with US

Putin has proposed that Moscow and Washington agree to adhere to the treaty's main provisions for another year

Russia said on Thursday it regretted the expiry of its last remaining nuclear arms treaty with the United States but would act responsibly after the removal of constraints on deployment of the world's deadliest weapons.

The New START treaty, which set limits on each side's missiles, launchers and strategic warheads, was the last in a series of nuclear agreements dating back more than half a century to the Cold War.

Security experts say its expiry will make it harder for the world's biggest nuclear powers to accurately gauge each other's intentions, raising the risk of misunderstandings. Some fear a new arms race, with China embarked on a nuclear build-up.

Russian President Vladimir Putin had proposed that Moscow and Washington agree to adhere to the treaty's main provisions for another year. US President Donald Trump did formally respond but has said he wants a better deal, bringing in China.

Beijing has declined negotiations with Moscow and Washington as it has a fraction of their warhead numbers - an estimated 600, compared to around 4,000 each for Russia and the US.

"What happens next depends on how events unfold," Kremlin spokesman Dmitry Peskov said.

"In any case, the Russian Federation will maintain its responsible and attentive approach to the issue of strategic stability in the field of nuclear weapons and, of course, as always, will be guided first and foremost by its national interests."

The White House said this week that Trump would decide the way forward on nuclear arms control, which he would "clarify on his own timeline".

CONFUSION OVER EXACT TIMING

There was confusion over the exact timing of the expiry, with neither the US State Department nor Russia's Foreign Ministry giving a precise time. Peskov said it would be at the end of Thursday.

Former Russian President Dmitry Medvedev, who signed the treaty with then US President Barack Obama in 2010, said on Wednesday that New START and its predecessors were now "all in the past".

Russia's Foreign Ministry said Moscow's assumption was that the treaty no longer applied and both sides were free to choose their next steps.

Criticising the "mistaken and regrettable" US approach, it said Russia was prepared to take "decisive military-technical countermeasures to mitigate potential additional threats to national security" but was also open to diplomacy.

China said on Thursday the expiration of the treaty was regrettable, and urged a resumption of dialogue on "strategic stability".

Ukraine, which has been at war with Russia since Moscow's 2022 invasion, said the treaty's expiry was a consequence of Russian efforts to achieve the "fragmentation of the global security architecture".

"Putin now uses it as another tool for nuclear blackmail to undermine international support for Ukraine," Ukraine's foreign ministry said.

UN CHIEF SAYS NUCLEAR RISK IS HIGHEST IN DECADES

Strategic nuclear weapons are the long-range systems that each side would use to strike the other's capital, military and industrial centres in the event of a nuclear war.

They differ from so-called tactical nuclear weapons that have a lower yield and are designed for limited strikes or battlefield use.

The absence of a treaty framework that provides stability and predictability could make it harder for each side to read the other's intentions and add to their arsenal, based on worst-case assumptions, analysts said.

Each could within a couple of years deploy hundreds more warheads beyond the New START limit of 1,550, experts say.

"Transparency and predictability are among the more intangible benefits of arms control and underpin deterrence and strategic stability," said Karim Haggag, director of the Stockholm International Peace Research Institute.

"Without them, relations between nuclear weapon states are likely to be more crisis prone - especially with artificial intelligence and other new technologies adding complexity and unpredictability to escalation dynamics and a worrying lack of diplomatic and military communication channels between the USA and both China and Russia."

UN Secretary-General Antonio Guterres 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."

He urged the sides to resume negotiations without delay to agree a successor framework restoring verifiable limits.