Former Russian president Dmitry Medvedev has become embroiled in a tense back-and-forth on social media that prompted U.S. President Donald Trump to announce he had ordered the re-positioning of two U.

Dmitry Medvedev has traveled a long way from his time as Russian president, when he once stood beside then-US President Barack Obama and declared that “the solution of many world problems depends on the joint will of the United States and Russia.

Former Russian president Dmitry Medvedev, whose comments prompted US President Donald Trump to move two nuclear submarines, was once seen as a liberal reformer but has become one of the Kremlin's most prominent anti-Western hawks.