Russia has intercepted a US spy plane at a time of escalating military tensions between the two powers. Earlier today, the Russian National Defence Control Centre (RNDCC) said a Russian MiG-31 fighter had escorted a US spy plane away from Russia’s borders. In chilling footage, the American plane – a RC-135 US Air Force reconnaissance aircraft – can seen from the cockpit of the Russian warplane off the coast of the Kamchatka peninsula in Russia.

The Russian warplane had scrambled amid concerns that the US spy plane was about to “violate its state border”.

The RDNCC said that after escorting the foreign plane from the border, the Russian fighter safely returned to its airbase.

This follows mounting tensions along the Ukraine border with Russia, amid fears of an all-out war between the two sides.

Russian President Vladimir Putin has amassed tens of thousands of troops and heavy military equipment close to the border with Ukraine in recent days.

Kiev estimates there are now 85,000 Russian troops just six miles from its border and in Crimea.

The US, which is strongly allied to Ukraine, is sending two warships to the Black Sea, while Russia is also boosting its navy deployments in the area.

Earlier today, a top Russian official warned that Moscow could intervene in eastern Ukraine if Ukraine launches an assault on Russian-backed separatists there.

The official, Dmitry Kozak, said that Russian forces could intervene to “defend” Russian citizens.