MOSCOW, Feb 10: A top general said on Tuesday Russia had started major exercises to test its nuclear forces amid concerns that changes in US military doctrine could "lower the threshold" for the use of nuclear arms.

But First Deputy Chief of the General Staff Yuri Baluyevsky denied Moscow was indulging in any "sabre rattling" towards the West or seeking to boost President Vladimir Putin's re-election campaign.

"The training is already under way," Colonel-General Baluyevsky said at a news conference. "Its main theme is averting power pressure on the Russian Federation," he added, referring to a widespread assumption among military chiefs that Russia's nuclear arsenal is its main guarantee of independence amid a decline in cash-strapped conventional forces.

Russia's media have said the planned military exercises would involve strategic nuclear forces, up to 40 per cent of ground troops and a third of reserves.

The reports have compared them to Soviet nuclear manoeuvres in 1982 - which sent tremors through the Western defence community - and said they were aimed at bolstering Mr Putin ahead of March 14 polls he seems almost certain to win.

Colonel-General Baluyevsky said there was nothing unusual about the latest exercises, which started last month and will involve firing strategic missiles from submarines and ground bases as well as flights by long-range bombers. He said they were little different in scale from those held over the past two years.

BUSH DOCTRINE: The Russian official said the exercise did not assume any specific potential adversary, but made clear that its planners had in mind US President George Bush's strategic doctrine.