Cuba has criticised the United States for prolonging a decision on the fate of a six-year-old Cuban boy at the centre of an international custody battle.

Foreign Minister Felipe Perez Roque condemned what he called delaying tactics designed to prevent Elian Gonzalez's return, after US immigration officials deferred a meeting with the boy's relatives in Miami until 21 January.

"We have heard about [the postponement], but we do not think there is any other solution than returning the boy to his father," Mr Roque told reporters in Havana.

"We do not acknowledge the competence of the courts in Florida ... Our understanding is that boy could be returned to his father at any time."

US authorities said the delay - to allow them more time to gather information - had no bearing on the decision on who should have custody of the child.

But they said there were no immediate plans to take the boy away from his great-uncle and cousin before the rescheduled meeting.

"This is a very complex case," Karen Kraushaar, a spokeswoman for the Immigration and Naturalization Service, said.

"A number of individuals claim to speak for the child. The question is who can speak for him and that's what we are trying to find out."

Protests

Elian was taken into the care of his Miami relatives after being shipwrecked during an illegal attempt to reach Florida last month. His mother and stepfather and a number of other asylum-seekers died during the crossing.

Elian's relatives have begun legal moves to keep him, but his father in Cuba is demanding his immediate return, arguing that his ex-wife, with whom he shared custody of Elian, did not get his permission to take the child.

Mr Gonzalez's call has been echoed in large, daily protests in Havana organised by the government.

Thousands of people - many in T-shirts showing Elian's face behind bars - gathered for the latest demonstration on Thursday outside the US Interests Section in Havana.

They waved Cuban flags and chanted "Free Elian", "Long live Fidel" and "Socialism or death".