Trump orders Pentagon to begin testing nuclear weapons 'immediately' The U.S. voluntarily halted nuclear explosive testing in 1992, though it has the ability to resume tests at a site in Nevada. https://www.nbcnews.com/news/amp/rcna240681 GYEONGJU, South Korea — President Donald Trump said Wednesday he had instructed the Defense Department to “immediately” resume testing nuclear weapons. “Because of other countries testing programs, I have instructed the Department of War to start testing our Nuclear Weapons on an equal basis,” Trump said on Truth Social shortly before his highly anticipated meeting with Chinese President Xi Jinping in South Korea. “That process will begin immediately.” The United States has voluntarily halted nuclear explosive testing since 1992. However, it has the ability to resume tests at the Nevada National Security Site.