Ukrainian President Volodymyr Zelenskyy's top adviser urged the U.S. to "strangle" Russia's economy by imposing secondary sanctions on Moscow's trading partners.

WASHINGTON (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.

US President Donald Trump said Friday he was ordering two US Navy nuclear submarines to “appropriate regions,” in response to remarks by Dmitry Medvedev, Russia’s former president and current deputy chairman of its Security Council.