The New START agreement, which was signed by Barack Obama, then the US president, and Dmitry Medvedev, then the Russian president, imposes restrictions on both countries, limiting their number of deployed nuclear warheads to no more than 1,550, and the number of deployed missiles and bombers to no more than 700.
Source: http://www.euronews.com/2025/09/22/russia-to-respect-nuclear-arms-limits-with-us-for-one-more-year-putin-says