The issue was reportedly discussed on the sidelines of the Ukraine peace talks in Abu Dhabi

Moscow and Washington are working on a deal to continue the New START nuclear reduction treaty, Axios reported on Thursday, citing three sources familiar with the issue. The strategic arms control agreement officially expired on February 5.

Signed in 2010, the treaty put caps on the number of strategic nuclear warheads and launchers that can be deployed and establishes monitoring mechanisms for both Russian and American arsenals. It was initially set to expire in 2021 but was extended for five years at the time.

According to Axios, President Donald Trump's son-in-law Jared Kushner and special envoy Steve Witkoff discussed the issue with the Russian delegation on the sidelines of the Ukraine peace talks in Abu Dhabi. "We agreed with Russia to operate in good faith and to start a discussion about ways it could be updated," a US official told the media outlet. Another source claimed that the sides had agreed to observe the treaty's terms for at least six months as the talks on a potential new deal would be ongoing.

Earlier on Thursday, Kremlin spokesman Dmitry Peskov said that Moscow suggested sticking to the treaty's provisions for another year but its initiative "remained unanswered." Russia will "keep its responsible attentive approach in the field of strategic stability [and] nuclear weapons" but will be always "primarily guided by its national interests," he said.

The UN also called the treaty expiration "a grave moment for international peace and security." Secretary-General Antonio Guterres warned that "the risk of a nuclear weapon being used is the highest in decades" as he urged Moscow and Washington to negotiate a successor framework.

Russian President Vladimir Putin had earlier proposed to his US counterpart Donald Trump a one-year extension of the treaty but the American president said that he wanted a "better" agreement that includes China.

On Thursday, Peskov said that China considers joining the talks on a new treaty "pointless" since its nuclear arsenal is incompatible with that of Russia and the US. "We respect this position," the Kremlin spokesman said.