Russia urged caution after Trump claimed he redeployed nuclear subs in response to provocative remarks by a senior Russian official.

Russia said on Monday that everyone should be "very, very careful" about nuclear rhetoric, responding to a statement by U.S. President Donald Trump that he had ordered a repositioning of U.S. nuclear submarines.

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