Trump also rebuked Medvedev in July, accusing him of throwing around the "N (nuclear) word" after the Russian official criticised U.S. strikes on Iran and said "a number of countries" were ready to supply Iran with nuclear warheads.

President Donald Trump has ordered the repositioning of two U.S. nuclear submarines. Friday's decision comes after what he calls "highly provocative statements" by former Russian President Dmitry Medvedev.

"Based on the highly provocative statements of the Former President of Russia, Dmitry Medvedev, who is now the Deputy Chairman of the Security Council of the Russian Federation, I have ordered two Nuclear Submarines to be positioned in the appropriate regions,