The US European command has released dramatic video footage that it says shows Russian fighter aircraft dumping fuel on a US drone before ramming it, forcing it to crash.

The encounter took place in international airspace over the Black Sea earlier this week, raising tensions between the superpowers. 

Russia's ambassador to the US later defended the Russian fighters' action, arguing that the drone was of a type that could carry weapons, and it was right on Russia's doorstep. He asked what the US would have done if a Russian drone was just off San Francesco or New York.

The US insisted the drone was observing international law and flying in international airspace. It described the Russian action as reckless and said such flights would continue. 

'Unsafe and unprofessional'

On Thursday the US released the 42-second footage showing aircraft making two close passes to the drone before the image breaks up. 

It was released with a note saying that two Russian Su-27 aircraft had "conducted an unsafe and unprofessional intercept" with its MQ-9 drone operating within international airspace. 

"Russian Su-27s dumped fuel upon and struck the propeller of the MQ-9, causing US forces to have to bring the MQ-9 down in international waters," it said.

The caption also noted that the video was edited for length, "however, the events are depicted in sequential order.”

On Wednesday the Russian defence minister told the Pentagon that increased US spying on Russia led to the incident. 

Sergei Shoigu told US Defense Secretary Lloyd Austin that "increased intelligence activities against the interests of the Russian Federation" and "non-compliance with the restricted flight zone" declared by Moscow due to its campaign in Ukraine had led to the incident.

The ministry in Moscow also warned that it would react "proportionately" to any future US "provocations".