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.

“He’s entering very dangerous territory!” the U.S. president warned on social media.