Russia is talking to the US about agreeing the details a treaty that placed limits on deployed nuclear weapons and missile launchers, its Foreign Ministry has said.

Russian Deputy Foreign Minister Sergey Ryabkov met his US counterpart Thomas Shannon in the Finnish capital Helsinki on Tuesday night to discuss implementing a provision of the 2010 Strategic Arms Reduction Treaty (New START) by the February 2018 deadline.

The treaty obliges the two biggest nuclear powers to limit the number of deployed warheads to 1,550 each, and 700 deployed missiles and bombers, by February.