MOSCOW: Russia and the United States on Tuesday were edging closer to breaking an impasse in long-running talks aimed at extending a landmark nuclear arms deal, due to expire within months.

US officials said they were ready to meet Russian diplomats as soon as possible, shortly after Moscow stated it could compromise on an American demand.

The two sides have struggled to find common ground over the fate over the New START treaty, which limits both sides to 1,550 deployed warheads but is due to expire next February.

While the US wants to rework the deal to include China and cover new kinds of weapons, Russia is willing to extend the agreement for five years without any new conditions - and each side has repeatedly shot down the other's proposals.

The agreement was signed in 2010 at the peak of hopes for a "reset" in relations between the two countries.

Together with the Cold War-era Intermediate-Range Nuclear Forces (INF) treaty, it was considered a centrepiece of international arms control.

However, the United States withdrew from the INF last year after accusing Moscow of violations.