Venezuelan President Hugo Chavez on Thursday urged U.S. President Barack Obama to return the military base of Guantanamo to Cuba after applauding his decision to close the prison for terrorism suspects there.

The anti-U.S. Cuba ally has tense relations with the United States and was been one of the most outspoken critics of former President George W. Bush, though he has kept open the possibility of improving ties with Obama.

"Now he should return Guantanamo and Guantanamo Bay to the Cubans because that is Cuban territory," he said in a speech at the World Social Forum in Brazil, a gathering of activists billed as an alternative to the Economic Forum of business leaders in Davos, Switzerland.

Shortly after taking over last week, Obama ordered that the Guantanamo Bay prison for terrorism suspects be closed within a year, showing a clear break from Bush's policies.

The United States took possession of the land around Guantanamo Bay in southeastern Cuba under a lease established after the 1898 Spanish-American War. In a 1903 agreement, Washington rented the land in perpetuity and pays a yearly fee. Since 1960 Cuba's communist government has refused to cash the checks.

The prison was set up to hold foreign terrorism suspects captured after U.S.-led forces invaded Afghanistan to root out al Qaeda and its Taliban protectors in response to the attacks of Sept. 11, 2001.

Chavez said he wants to improve relations with the United States but is waiting for further signs Obama will move away from U.S. "imperialism."

"Let's wait and see, I don't have many illusions, the empire is intact," he said. "In Venezuela we are prepared to resist 10 more years, 20 more years, 100 more years of imperialist aggression."