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

President Donald Trump has reportedly hinted that his nuclear submarines are now "in the region of Russia" after he ordered them there following a comment made by former Russian President Dmitry Medvedev.

Dmitry Medvedev has traveled a long way from his time as Russian president, when he once stood beside then-US President Barack Obama and declared that “the solution of many world problems depends on the joint will of the United States and Russia.