US President Donald Trump said Friday he was ordering two US Navy nuclear submarines to “appropriate regions,” in response to remarks by Dmitry Medvedev, Russia’s former president and current deputy chairman of its Security Council.

After a weeklong back-and-forth between Donald Trump and Dmitry Medvedev, Trump said in a post on Truth Social that he repositioned two nuclear submarines.

President Donald Trump issued a rare threat of nuclear escalation on Friday, saying he had ordered two nuclear submarines to be strategically positioned near Russia in response to what he said were aggressive remarks by Dmitry Medvedev, the country’s former president and current deputy chairman of its Security Council.