 U.S. preparing nuclear test site in Nevada, Moscow. The Russian Foreign Ministry warned the U.S. not to resume full-scale nuclear tests after President Vladimir Putin withdrew Moscow's ratification of the Comprehensive Test Ban Treaty in order to restore parity. The United States must understand that conducting full-scale tests for which the infrastructure in Nevada is reportedly prepared will force us to respond in kind, the ministry said in a statement. Last month, the U.S. Department of Energy's National Nuclear Security Administration carried out an underground detonation at a site northwest of Las Vegas with the purpose of improving the detection of underground nuclear explosive tests. The explosion involved chemical, high explosives, and radio tracers. The National Nuclear Security Administration said Moscow officially withdrew its ratification of the Comprehensive Test Ban Treaty, noting that the U.S. Congress had avoided ratifying the 1996 agreement for over 25 years under far-fetched pretexts. This couldn't go on forever, the Russian Foreign Ministry said, in conditions when the United States is pursuing a deeply hostile course towards our country, maintaining the previous imbalance in approaches to the Comprehensive Test Ban Treaty that has developed between Moscow and Washington turned out to be no longer possible. The U.S. has not conducted a live nuclear test since 1992. Russia has openly said it will not resume testing first, but will respond if the U.S. forces its hand.