Kremlin says it welcomes the U.S. readiness to extend the New START treaty on curbing nuclear weapons stockpiles, but warned that success will “depend on the details.”

Kremlin spokesperson Dmitry Peskov disclosed the position of the Kremlin on Friday, two days after the inauguration of the Joe Biden and Kamala Harris presidency in the U.S.

The New START (Strategic Arms Reduction Treaty) agreement went into effect in 2011 and is set to expire on Feb. 5, at which point there would be no deal between the U.S. and Russia setting controls on weapons stockpiles and allowing inspections.

Biden’s new administration proposed a five-year extension this week.

“Russia is for preserving New START and for extending this treaty in order to gain time for talks and contacts.

“We can only welcome the political will to extend this document,” said Peskov.

But he added that “everything will depend on the details of this proposal, which is yet to be studied.”

The U.S. proposal had already received support from other parts of Russia’s political elite.

Diplomat Mikhail Ulyanov called Biden’s move an “encouraging step” on Twitter.

“The extension will give the two sides more time to consider possible additional measures aimed at strengthening strategic stability and global security,” wrote Ulyanov, who represents Russia at international organisations operating in Vienna.

Russia has proposed an extension several times already, however arguing for no changes to the current deal and without stipulations.

“We’re already in a dialogue; we’re expecting concrete proposals,” said Leonid Sluzki, head of the foreign relations committee in the Duma, Russia’s parliament.

The two countries control about 90 per cent of the world’s nuclear weapons stockpile.

New START limits the two countries to 1,550 ready-to-launch nuclear warheads and 800 launch systems each.

The Trump administration had negotiated with Russia on the issue, but had been unable to reach a deal.