Russian fighter intercepted US Air Force plane

A Russian SU-27, shown in an August 2007 file photo, crossed the nose of the US aircraft, a Pentagon spokesman said

A Russian jet flew within 100ft (30m) of a US Air Force plane over international waters near Japan in April, US officials have said.

The incident on 23 April involved a Russian SU-27 Flanker fighter and a US intelligence-gathering RC-135U.

The US plane was flying a routine mission in international airspace over the Sea of Okhotsk, officials said.

The incident came amid tension between the US and Russia over Russia's involvement in Ukraine.

"The SU-27 approached the RC-135 and crossed the nose of the US aircraft," Lt Col Myles Caggins III told the BBC.

The Russian aircraft manoeuvred aggressively and exposed its belly to the American pilots to demonstrate it was armed with air-to-air missiles, Defense News and CNN reported.

US and Russian defence officials are said to have later discussed the incident.

Earlier in April, another Russian fighter jet made repeated low-altitude passes over US Navy destroyer Donald Cook in the Black Sea.

On Wednesday, US President Barack Obama condemned Russian "aggression" in Ukraine .

"We will not accept Russia's occupation of Crimea or its violations of Ukraine's sovereignty," Mr Obama said in Warsaw.

He and Russian President Vladimir Putin are expected to meet in France on Friday during 70th anniversary commemorations of the D-Day landings in Normandy.