Washington Times says Russia deployed 153 new nuclear warheads over the past year as its RS-24 Yars ICBMs and RSM-56 Bulava SLBMs entered service.
By Vitaly V. Kuzmin (http://vitalykuzmin.net/?q=node/558) [CC BY-SA 3.0 or CC BY-SA 3.0], via Wikimedia Commons
Each of these missiles can carry up to 10 nuclear warheads.
The number of warheads that Russia is fielding is way above the 1,550 warhead limit set by the 2010 New START arms treaty. The treaty requires Russia and United States to cut their number of strategic nuclear warheads to 1,550 by February 2018.