Russian President Vladimir Putin says that Russia is suspending its participation in a treaty aimed at keeping a lid on nuclear weapons expansion.
The so-called New START Treaty was signed by Russia and the U.S. in 2010. It caps the number of long-range nuclear warheads they can deploy and limits the use of missiles that can carry atomic weapons.
Putin said Tuesday in a major address that Russia was not fully withdrawing from the treaty yet.
He said Russia must stand ready to resume nuclear weapons tests if the US does so.