In 2017, during his first term as US president, Trump announced that he had sent two nuclear submarines to the Korean peninsula. Soon afterwards, he held a meeting with the North Korean leader, Kim Jong Un. Whether this latest move will lead to a new meeting with Putin is yet to be seen, however.

The Kremlin has tried to calm tensions in a feud between Trump and Medvedev that spiraled into nuclear threats.

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,