Donald Trump has reportedly ordered two nuclear submarines to be positioned closer to Russia after escalating a war of words with former Russian President Dmitry Medvedev.

The president posted on Truth Social on Friday, saying, “I have ordered two Nuclear Submarines to be positioned in the appropriate regions, just in case these foolish and inflammatory statements are more than just that.”

Trump and Medvedev, the deputy chairman of Russia’s Security Council, have been sparring online since Trump shortened his deadline for Russia to reach a ceasefire with Ukraine, lest the country incur his famous tariffs. Medvedev wrote on Monday that “each new ultimatum is a threat and a step towards war” with the U.S.

Trump fired back, telling the chairman to “watch his words.” Then Medvedev responded, warning Trump about the “fabled ‘Dead Hand,’” Russia’s secretive nuclear missile system, set to fire automatically if Moscow’s leadership is taken out.

Now Trump has responded by sending nuclear submarines—which have the capacity to launch nuclear weapons but do not necessarily carry them—to the “appropriate regions.”

Known for his hawkishness, Medvedev is generally regarded as nothing more than a “social-media attack dog” by Russian President Vladimir Putin and his circle, according to The New York Times. But luckily for Medvedev, we have a social media president. If only he wasn’t armed with the nuclear codes.