Heightened tensions with Russia stem from President Trump's ultimatum to Moscow: make peace with Ukraine or brace for sanctions and secondary tariffs.

The Russian and Chinese militaries practiced destroying an "enemy" submarine during joint naval drills Wednesday, just days after President Donald Trump moved a pair of nuclear submarines toward Russia,

WASHINGTON, Aug 1 (Reuters) - 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.