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,

U.S. President Donald Trump on Friday said he had ordered two nuclear submarines to be positioned in "the appropriate regions" in response to remarks from former Russian President Dmitry Medvedev about the risk of war between the nuclear-armed adversaries.

US President Donald Trump says he has ordered two nuclear submarines to "be positioned in the appropriate regions" in response to "highly provocative" comments by former Russian President Dmitry Medvedev.