After trading barbs online with former Russian leader Dmitri A. Medvedev, President Donald Trump has ordered nuclear submarines to be positioned in “the appropriate regions” near Russia “just in case.”

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.

Comments made by Russian Security Council Chairman Dmitry Medvedev on Thursday spurred President Donald Trump to reposition two U.S. nuclear submarines.