President Donald Trump has called on US military leaders to resume testing US nuclear weapons in order to keep pace with other countries such as Russia and China.
Because of other countries testing programs, I have instructed the Department of War to start testing our Nuclear Weapons on an equal basis, he wrote on social media just before meeting with Chinese President Xi Jinping in South Korea.
The US has more nuclear weapons than any other country, Trump said, with Russia second and China a distant third. It has not conducted nuclear weapons testing since 1992.
It comes just days after Trump denounced Russia for testing a nuclear-powered missile, which reportedly has an unlimited range.
Later, on Air Force One after the two leaders' meeting, Trump said the nuclear test sites would be determined later. With others doing testing, I think it's appropriate that we do also, Trump said on his way back to Washington.
No country except North Korea has conducted a nuclear test explosion in this century, according to the Arms Control Association (ACA).
Trump's announcement did not include details of how the tests would occur, but wrote the process will begin immediately.
His post on Wednesday night acknowledged the tremendous destructive power of nuclear weapons, but said he had no choice but to update and renovate the US arsenal during his first term in office.
He also said that China's nuclear programme will be even within 5 years.
The announcement marks an apparent reversal of a long-standing US policy. The last US nuclear weapons test was in 1992, before former Republican President George HW Bush issued a moratorium as the Cold War ended.
Russia announced over the weekend that it had successfully tested two new weapons capable of carrying nuclear warheads. These included a missile which the Kremlin said could penetrate US defence systems, and an underwater drone called Poseidon, capable of hitting the American west coast and triggering radioactive ocean swells.
But those tests did not involve the detonation of nuclear weapons.
Trump has said the US has more nuclear weapons than any other country. The exact number of warheads held by each country is kept secret in each case - but Russia is thought to have a total of about 5,459 warheads while the US has about 5,177, according to the Federation of American Scientists (FAS).
According to US think tank Center for Strategic and International Studies (CSIS), China has roughly doubled its nuclear arsenal in the past five years and is expected to exceed 1,000 weapons by 2030.
Trump's statement about nuclear testing came about 100 days before the expiration of the New Strategic Arms Reduction Treaty (New Start) in February 2026 - the last remaining nuclear arms treaty between the US and Russia.
The last time the US tested a nuclear bomb was 23 September 1992. The test took place at an underground facility in the western state of Nevada. The project, code named Divider, was the 1,054th nuclear weapons test conducted by the US, according to the Los Alamos National Laboratory.
Some experts note that it would take the US at least 36 months to restart underground nuclear tests at the former Nevada test site. Criticism from anti-nuclear advocates has stated that Trump is misinformed and out of touch, emphasizing that there is no justification for this move.
