An estimated 1,710 of the warheads that can be used by the Russian military are deployed on the likes of intercontinental ballistic missiles or at strategic bomber bases, the organization said. The U.S. has approximately 1,670 deployed strategic warheads, according to the FAS.

A decree signed by the Russian leader, though long planned, came days after President Biden authorized the use of U.S.-supplied missiles by Ukraine for strikes inside Russia.

Vladimir Putin has approved changes to Russia’s nuclear doctrine, setting out new conditions under which the country would consider using its arsenal. The doctrine now says an attack from a non-nuclear state, if backed by a nuclear power, will be treated as a joint assault on Russia.