WASHINGTON, Oct. 14 (Xinhua) -- U.S. Secretary of State Mike Pompeo said on Wednesday that Washington would welcome an agreement based on understandings reached recently with Moscow to extend a key arms control treaty.

"We would welcome the opportunity to complete an agreement based on understandings that were achieved over the last couple weeks about what the range of possibilities look like for an extension of New START (New Strategic Arms Reduction Treaty)," Pompeo said in a press briefing.

"I am hopeful that the Russians will find a way to agree to an outcome that, frankly, I think is in their best interest and in our best interest," he added.

Pompeo's optimism came one day after confusing remarks between U.S. and Russian officials over the extension of the New START, a key nuclear arms control treaty between Washington and Moscow that set to expire in months.

U.S. Special Presidential Envoy for Arms Control Marshall Billingslea suggested on Tuesday that the two sides have reached an agreement in principle "at the highest levels of our two governments" to extend the treaty.

"What we've indicated to the Russians is that we are in fact willing to extend the New START treaty for some period of time, provided that they, in return, agree to a limitation, a freeze, on their nuclear arsenal. We're willing to do the same," Billingslea said at a think tank event.

Russia, however, immediately pushed back Billingslea's position, denying such agreement exists.

According to Russian media reports, Russian Deputy Foreign Minister Sergei Ryabkov rebuffed Washington's position on freezing nuclear arsenals. "The U.S. position in favor of freezing has long been known to us, it is unacceptable to us."

The Russian chief negotiator also noted that Russia would refuse any agreement on the New START that was timed to coincide with the U.S. presidential election.

Billingslea and Ryabkov since June had held three rounds of negotiations in Vienna and Helsinki on arms control issues, without making substantive progress.

In 2010, Washington and Moscow signed the New START, which stipulates the limits to the numbers of deployed nuclear warheads and strategic delivery systems by both. The New START, the last remaining nuclear arms control treaty in force between the two nuclear superpowers, will expire on Feb. 5, 2021.

The agreement can be extended for at most five years with the consent of the two countries. Russia has expressed willingness to extend the treaty, while the Trump administration has declined to commit to extending it.