Russia said on Monday that everyone should be "very, very careful" about nuclear rhetoric, responding to a statement by U.S. President Donald Trump that he had ordered a repositioning of U.S. nuclear submarines.

As Trump orders US nuclear submarines into position, a closer look at the US vs Russia submarine power race, from fleet size to nuclear deterrence and strategic deployment

A massive 8.8-magnitude earthquake has sparked international concern over the safety of Russia’s strategic nuclear submarine base at Avacha Bay, located just 75 miles from the quake’s epicentre.