"Former president Boris Yeltsin died today," the spokesman said on Monday.

Yeltsin was known to have suffered from heart problems and is reported to have died of coronary and vascular failure. Russia's Interfax news agency quoted an anonymous medical source as saying the former president died of heart failure.

Presidential predecessor and political rival Mikhail Gorbachev extended his sympathies to Yeltsin's family on Monday, saying Yeltsin had performed a great service to his country but also committed "serious mistakes."

"I offer my deepest condolences to the family of a man on whose shoulders rested many great deeds for the good of the country and serious mistakes -- a tragic fate," the former Soviet leader was quoted by Interfax as saying.

Yeltsin, who won two presidential elections and was post-Soviet Russia's first leader, was largely regarded in his own country as a contradictory figure. Though admired for his defiance of the Soviet system, he also led the country in a crushing war in Chechnya.

"A historic figure"

A man with a penchant for flamboyant gestures, Yeltsin will perhaps be best remembered around the world for bravely clambering onto a tank sent into Moscow in 1991 by communist hardliners attempting a coup in the dying days of the Soviet Union.

He then introduced historic reforms that dragged a bankrupt communist economy into the modern age, unleashed political pluralism and allowed a vibrant, freewheeling media.

"I think he will always be remembered as the man who brought down communism," said Yeltsin's former advisor, Alexander Nekrasov, told Britain's Sky News. "That's what his legacy is."

An overwhelming majority of Russians continue to blame Yeltsin for Russia's slide from superpower status to economic basket case and second fiddle to the United States on the international stage.

The White House on Monday mourned Yeltsin as "a historic figure" and offered its condolences to his widow, his relatives, and all of Russia.

"He was an historic figure during a time of great change and challenge for Russia. Our condolences go to Mrs Yeltsin, their family and the people of Russia," said national security spokesman Gordon Johndroe.

Born to a peasant family in 1931 near the Ural Mountains city of Ekaterinburg, Yeltsin became a construction engineer before embarking on a political career in the Communist Party.

He was elected the Russian Federation's first president in June 1991 and served until Dec. 31, 1999, resigning for health reasons several months before his term ended and handing over power to then Prime Minister Vladimir Putin.

One of Putin's first acts in office was to grant Yeltsin immunity from prosecution, sparing him the fury of those who blamed him for trading away valuable state assets, starting two bloody wars in Chechnya and allowing the 1998 economic collapse.