NATO on Friday called on Russia to respond "in a positive way" to the US proposal to extend the New Strategic Arms Reduction Treaty (START) for another five years.
"I welcome [US] President [Joe] Biden's announcement and his intention to seek an extension of the New START treaty," said NATO chief Jens Stoltenberg in a news conference with President of Georgia Salome Zourabichvili.
"I have stated repeatedly that we should not end up in a situation where we have no agreement, no limitation whatsoever on the number of nuclear warheads," Stoltenberg added.
The Biden administration said Washington wants a five-year extension to the treaty, which is due to expire on Feb. 5.
"This extension makes even more sense when the relationship with Russia is adversarial as it is at this time," White House spokeswoman Jen Psaki said at a news briefing on Thursday.
Russia on Friday welcomed the US' announcement, and Kremlin spokesperson Dmitry Peskov said Moscow shares the same view on the New START agreement, but is waiting to see "details of this proposal".
"We can only welcome the political will to extend this document, but everything will depend on the details of this proposal, which is yet to be studied," he said.
The NATO chief said the New START agreement should not be left to demise like other arms control agreements and all NATO allies support the New START agreement.
"Having said that, the extension of the New START treaty is not the end. It should be at the beginning of renewed efforts to strengthen international arms control to look into how we can cover more weapon systems, and also include more nations, for instance, China," noted Stoltenberg.
"I call on Russia to respond in a positive way to the US proposal. This is bilateral agreement between the United States and Russia. The United States has consulted closely with the NATO allies on the New START, and the possibility of extending the treaty," he said.
The New START treaty, signed in 2010 by former US and Russian leaders, Barack Obama and Dmitry Medvedev, limits the number of strategic nuclear warheads both countries can deploy to 1,550.
It also restricts the number of intercontinental ballistic missiles, submarine-launched ballistic missiles, and bombers equipped to deliver nuclear weapons to 700, and includes inspections to verify compliance with the deal.