US President George W. Bush labeled Cuba as "a tropical Gulag," and vowed to keep US economic embargo on the neighboring island country.

"As long as the regime maintains its monopoly over the political and economic life of the Cuban people, the United States will keep the embargo in place," Bush said in a speech at the State Department.

Washington began imposing economic sanctions on Cuba after Fidel Castro started the Cuban Revolution in 1959.

He said he had ordered Secretary of State Condoleezza Rice and Cuba-born US Commerce Secretary Carlos Gutierrez to seek contributions for a billion-dollar "freedom fund" tied to future democratic reforms in Havana.

"Now is the time to stand with the Cuban people as they stand up for their liberty. Now is the time for the world to put aside its differences and prepare for Cubans' transition to a future of freedom and progress and promise."

"The dissidents of today will be the nation's leaders tomorrow. When freedom finally comes, they will surely remember who stood with them," he said.

A senior official at the White House told reporters Tuesday that the fund will be used "to support Cubans and the rebuilding of their country when there is a government in place that is respecting fundamental freedoms."

"The international community needs to be prepared for that moment of change," said the anonymous official who is indicating that the democratic shift Washington hopes will follow the death of Cuban leader Fidel Castro.

Castro, 81, underwent an intestinal operation in July 2006 and later handed over power to Cuban Defense Minister Raul Castro.

(Xinhua News Agency October 25, 2007)