"Even though the United States has reduced the number of warheads deployed on its long-range missiles and bombers, consistent with the terms of the 2010 New START Treaty, it also plans to develop new delivery systems for deployment over the next 10-30 years. The 115th Congress will continue to review these programs, and the funding requested for them, during the annual authorization and appropriations process.
During the Cold War, the U.S. nuclear arsenal contained many types of delivery vehicles for nuclear weapons. The longer-range systems, which included long-range missiles based on U.S. territory, long-range missiles based on submarines, and heavy bombers that could threaten Soviet targets from their bases in the United States, are known as strategic nuclear delivery vehicles. At the end of the Cold War, in 1991, the United States deployed more than 10,000 warheads on these delivery vehicles. With the implementation of New START completed in February 2018, the United States is limited to 1,550 accountable warheads on these delivery vehicles, a restriction that will remain in place at least through 2021, while New START Treaty remains in force.
At the present time, the U.S. land-based ballistic missile force (ICBMs) consists of 400 landbased Minuteman III ICBMs, each deployed with one warhead, spread among a total of 450 operational launchers. This force is consistent with the New START Treaty. The Air Force is also modernizing the Minuteman missiles, replacing and upgrading their rocket motors, guidance systems, and other components, so that they can remain in the force through 2030. It plans to replace the missiles with a new Ground-based Strategic Deterrent around 2029.."Strategic nuclear forces