Sukhoi 27 fighter jet
Two Russian Sukhoi Su-27 fighter jets intercepted a US spy plane over the Black Sea last month, with one coming dangerously close, said the PentagonWikipedia

In a frightening close encounter of the cold war kind a Russian fighter jet roared within 10 feet (3 m) of a US Air Force spy plane over the Black Sea, CNN reports.

The "unsafe intercept" was conducted in international airspace in an "unprofessional and inappropriate" manner, charged Pentagon spokesman Colonel Steve Warren.

Two Russian Sukhoi Su-27 fighter jets conducted separate intercepts of a large US RC-135 reconnaissance aircraft on 30 May, reports ABC News. The first of the two came dangerously close when the Russian pilot flew behind the American plane, then roared beneath it before veering off to the right side, according to Warren.

It wasn't immediately clear if the encounter was intended to be threatening or a demonstration of the pilot's "lack of training," said Warren in a back-handed slam at Russia.

"The reason it concerns us is that these unsafe intercepts can lead to accidents and potentially tragedy or miscalculations of some sort and that is not what we want to see," Warren said.

The US has filed a formal complaint with the Russians over the near miss.

Last month the US released a video showing a Russian fighter buzzing a US Navy destroyer. In April the US also filed a complaint after another Russian jet made repeated passes over a US spy plane over the Baltic Sea.

Airspace in the region has been tense lately with massive air war games early this month over the Arctic by both Russian and Nato forces.