The weapon, capable of breaching anti-missile defence systems, flew almost the whole length of the country.

US plans to build a missile defence shield in Europe have angered Russia, which sees the proposal as a challenge to its influence in the region.

The Russian test comes as President Vladimir Putin heads for the US to meet President George W Bush on Sunday.

'Key component'

The Bulava missile was launched from the White Sea off Russia's north-west coast.

The intercontinental missile hit its target on the Pacific Ocean peninsula of Kamchatka.

Three earlier tests of the weapon in recent years had failed.

The Bulava is designed to have a range of 10,000km (6,200 miles) and carry six individually targeted nuclear warheads.

Russian President Vladimir Putin has described the missile as a key component of Moscow's future nuclear forces, saying it can penetrate any prospective missile defence system.