President Vladimir Putin has drawn a "red line" for the United States and its allies by signalling that Moscow will consider responding with nuclear weapons if they allow Ukraine to strike deep inside Russia with long-range Western missiles.

Dmitry Medvedev, a long-time ally of Russian President Vladimir Putin, has laid out the country's new deterrence policy against Western "aggression," and warned that provocations by Ukraine and its allies could result in nuclear war.

Russian President Vladimir Putin has drawn a new nuclear “red line” for the West, warning that Moscow could respond with nuclear weapons if Ukraine is allowed to use Western long-range missiles to strike inside Russia. This comes as tensions rise with Ukraine’s ongoing requests for additional military aid from the U.S. and its allies.