Manuel Zelaya has seen his popularity ratings plummet

If Honduras fails to comply, it could face being suspended from the group.

Caribbean nations have issued strong condemnations of the coup.

The army ousted Mr Zelaya on Sunday over his plans for constitutional reform, which his critics said were aimed at prolonging his presidency.

Mr Zelaya denies seeking to extend his term and has vowed to return, but he has been warned he faces arrest.

Roberto Micheletti, the Speaker of Congress who was sworn in as interim president, said Mr Zelaya would face charges of violating the constitution, and having links with organised crime and drug-traffickers.

Emergency

Guyana was among the first Caribbean countries to criticise the overthrow.

"In accordance with the principles of democracy and the tenets of the Inter-American Democratic Charter, the Government of Guyana is concerned with the breakdown of the constitutional order in the Republic of Honduras that has occurred as a result of the coup d'état," a statement issued in Georgetown said.

The charter is an OAS article and after an emergency meeting of the organisation, its secretary-general Jose Miguel Insulza condemned what he described as "an old-fashioned coup" in Honduras.

"We need to show clearly that military coups will not be accepted," he said.

"If within 72 hours the reinstatement doesn't happen, the assembly ... will meet again to suspend Honduras."

But Belize, the only Caricom nation with full diplomatic representation in Tegucigalpa, has cautioned that there may be no easy solution to the issue.

"... this is not an ordinary military coup; it is not a group of colonels that decided that we will do this and overthrow the government," said Fred Martinez, the Belize ambassador in Honduras.

Worrisome

Mr Zelaya, 57, was ousted amid stiff opposition to his proposals to amend the constitution from the courts, military, Congress and even some members of his own party.

"So it's a huge sector of (Honduran) society and we have a deeply divided country, very worrisome for our neighbour. There is no simple solution," Mr Martinez told Channel Five television in Belmopan.

Mr Zelaya has said he would return home this week, accompanied by Mr Insulza and the presidents of Argentina and Ecuador.

However, it is not clear if his plans will be delayed until the weekend given the OAS deadline.

	The presidential palace in Honduras is under guard

Mr Zelaya, 57, was ousted after he tried to push through a non-binding referendum on constitutional change.

His critics say this could have paved the way for the president - elected in 2006 and restricted to only one term - to run for re-election. The Supreme Court and Congress deemed the ballot illegal.

The vote had been set for Sunday, but instead troops stormed the presidential palace at dawn, bundled the president to an airbase and flew him to Costa Rica.

Falling Popularity

Speaking at the UN General Assembly on Tuesday, Mr Zelaya said he was not aiming to stay in office but was determined to complete his term which ends in January 2010.

"I am not going to convene a constitutional assembly, and if I was offered the possibility of remaining in power, I would not do it. I am going to fulfil my four years, I'm going to fight to have the four years respected," he said.

The UN passed a resolution on Tuesday calling "firmly and categorically on all states to recognise no government other than that" of Mr Zelaya.

But thousands of people have been demonstrating in Tegucigalpa against the return of the ousted leader, whose popularity has slumped in opinion polls to around 30% in recent months.

The BBC's Stephen Gibbs in Tegucigalpa says they are very determined to prevent him being reinstated and appear to outnumber his supporters, at least in the capital.

On Monday, groups of his supporters defied a curfew, clashing with police in the city centre.