President Donald Trump announced that he had ordered the deployment of a pair of U.S. nuclear submarines amid escalating threats and rhetoric with a top Russian official over his deadline to end Russia's war in Ukraine.

The new move of the nuclear submarines to 'appropriate regions' appears mostly symbolic – the U.S. already has a fleet of dozens of nuclear-powered subs that are constantly ready to strike in the event of a conflict.

Nevertheless, it notches up the tensions once again after Trump announced he was moving up his ultimatum for Russia to agree to end the war.

If Russia fails to strike a peace deal by the end of next week, Trump said he will impose punishing 'secondary sanctions' on nations who trade with Russia.

Trump made the decision to deploy the submarines after 'highly provocative statements' of Russia's ex-President Dmitry Medvedev - who now serves as deputy of Russia's Security Council.