In 2002, the United States and Russia agreed in the SORT treaty to reduce their deployed stockpiles to not more than 2,200 warheads each. In 2003, the U.S. rejected Russian proposals to further reduce both nation's nuclear stockpiles to 1,500 each. In 2007, for the first time in 15 years, the United States built new warheads. These replaced some older warheads as part of the Minuteman III upgrade program. 2007 also saw the first Minuteman III missiles removed from service as part of the drawdown. Overall, stockpiles and deployment systems continue to decline in number under the terms of the New START treaty.