US bombers accused of rehearsing nuclear strike on Russia

Russia's Defence Minister Sergei Shoigu accused US bombers of rehearsing a nuclear strike on Russia from two different directions earlier this month and complained that the planes had come within 20 kilometres of the Russian border. But, the Pentagon said, its drills were announced publicly at the time and adhered to international protocols.

Moscow's accusation comes at a time of high tension with Washington over Ukraine, with US officials voicing concerns about a possible Russian attack on its southern neighbour - a suggestion the Kremlin has dismissed as false.

Moscow has in turn accused the United States, NATO and Ukraine of provocative and irresponsible behaviour, pointing to US arms supplies to Ukraine, Ukraine's use of Turkish strike drones against Russian-backed separatists in eastern Ukraine and NATO military exercises close to its borders.

Mr Shoigu said that Moscow had noted a significant increase in the activity by U.S. strategic bombers, which he said had carried out 30 flights close to Russia this month. That, he said, was 2.5 times more than the same period last year.