Speaking to military chiefs and Russian defense executives, Putin said the decision must be made quickly on the soon-to-expire document, and Washington's position is so far unclear.

"Russia is ready to renew the New Start treaty without delay, as quickly as possible, before the end of this year," Putin said.

"I can say this officially so that later there are no double or triple interpretations of our position," he said.

Cold War rivals Russia and the United States have ripped up the Soviet-era Intermediate Range Nuclear Forces (INF) treaty this year, blaming one another for its demise.

That deal was seen as a cornerstone of global security and its burial sparked fears of a new armed race. Putin on Thursday sought to discuss "measures to respond to potential dangers" associated with US withdrawal from the INF.

Washington has signalled little interest in committing to the New Start treaty for another five years past its expiration in February 2021, pointing out a desire to move beyond bilateral constraints.

The New Start, inked in 2010 by then-presidents Barack Obama and Dmitry Medvedev during a much warmer period in US-Russia relations, is seen as the last key nuclear deal still standing which keeps the arsenals of both countries below their Cold War peak.

The treaty obliged the sides to halve their numbers of strategic nuclear missile launchers and establish a new verification regime.

Putin's pledge to renew the treaty came a day after the Committee on Foreign Affairs in the US House of Representatives held a hearing on the importance of the treaty Wednesday.

Former under secretary for arms control and NATO deputy secretary general Rose Gottemoeller warned that "things could change drastically and quickly" without the treaty and possibly lead the US to a "strategic crisis".