HAVANA - US PRESIDENT Barack Obama uses 'lies' to back up his refusal to change US policy toward Cuba and maintain the US economic embargo, former president Fidel Castro said on Wednesday.

'We would better understand the real limitations the new US president is facing to change his country's policy toward our homeland, if he didn't use lies to justify his actions,' Castro wrote in an opinion article that appeared in the government-run website cubadebate.com.

At a weekend Summit of the Americas in Trinidad and Tobago, Mr Obama said that while 50 years of US policy 'hasn't worked' to change Cuba, the 47-year economic embargo would stay in place until Cuba gave more freedoms to its people.

'We're not going to change that policy overnight,' Mr Obama told a news conference at the end of the summit of 34 heads of government.

Since taking office in January, however, Mr Obama has lifted travel and money transfer restrictions on Cuban-Americans with relatives in Cuba.

Mr Castro lambasted Mr Obama for keeping the Cuba policy of his predecessor George W. Bush virtually intact, including the embargo and US-run anti-Cuban radio and television broadcasts.

'Must we accept the United States' right to maintain the blockade for the duration of a geological era until capitalist democracy reaches Cuba?' asked the aging former leader.

'We haven't asked for the capitalist democracy you grew up under and fervently - and rightly so - believe in,' Mr Castro told Mr Obama.

'We don't pretend to export our political system to the United States,' he added in his article, titled 'The Summit and the Lie.' Mr Castro regretted that the US 'embargo was not even mentioned' in the summit's final declaration, which a number of participants did not sign.

Several nations, including Bolivia, Venezuela, Honduras and Nicaragua, agreed ahead of time not to sign the final declaration to show displeasure that Cuba was not invited to the summit. -- AFP