US Secretary of State Mike Pompeo has pressed for immediate negotiations with Russia to finalize a verifiable agreement as the two sides seem moving closer to extend a key nuclear arms control treaty.
"Russia has agreed in principle to freeze all of its nuclear warheads... But we need to make sure that US and Russian negotiators get together just as soon as possible to continue to make progress to finalize a verifiable agreement," Pompeo was quoted in media as saying.
His remarks came at a time when the two nuclear superpowers appear to reach common ground on the one-year extension of the New Strategic Arms Reduction Treaty (New START), which will expire in February 2021.
Washington and Moscow signed the New START in 2010.
The treaty, which stipulates limits to the numbers of deployed strategic nuclear warheads and delivery systems, is the last remaining nuclear arms control pact in force between the two nuclear superpowers.
The New START can be extended by a maximum of five years with the consent of the two countries.
Without an extension, the US and Russian nuclear arsenals would be unchecked for the first time since 1972.
US and Russian officials had held several rounds of negotiations over arms control in Vienna and Helsinki since June, without making substantive progress.
Meanwhile on Wednesday, Russia confirmed its readiness to continue negotiations with the US on the extension of the New START.
"This topic is of strategic nature and global significance. It is in the interests of not only our two countries but also global security and stability," Kremlin spokesman Dmitry Peskov said.
He said Russia hopes that the dialogue with the US will continue and their differences will be overcome.
The Russian Foreign Ministry said on Tuesday that the country was ready to freeze its existing number of nuclear warheads along with the US to extend the New START by one year.
Whether an agreement can be reached by the two sides is still an open question.
The Trump administration had long complained that the New START only constraints deployed strategic nuclear warheads and delivery systems for both, but not tactical ones that Russia heavily equipped.
In its Tuesday statement, Russia made it clear that the freeze of nuclear warheads was a "political commitment" and "not be accompanied by any additional demands on the part of the US", while Washington immediately imposed verification condition, casting doubt on whether the two sides were genuinely moving closer.