The Organization of American States planned a mission to Honduras to seek the restoration of ousted President Manuel Zelaya as interim leaders tried to shore up support for the coup against him.
OAS Secretary-General Jose Miguel Insulza said in Guyana on Thursday he will travel to Honduras on Friday with staff members to talk with the caretaker government there.
The OAS, which groups most of the countries in the Western Hemisphere including the United States, has given Honduras' caretaker government until Saturday to restore Mr. Zelaya or be suspended from the body.
The Honduran administration has so far rebuffed any attempts to bring back Mr. Zelaya, who was ousted in a military coup last Sunday in a dispute over presidential term limits. But the OAS visit could represent the first chance of a negotiated settlement to the biggest political crisis in Central America in 20 years.
The coup in Honduras has become a test of regional diplomacy and of U.S. commitment to shoring up democracy in Latin America.
Honduran coup backers, headed by interim leader Roberto Micheletti, argue that Mr. Zelaya's ouster was legal as it was ordered by the Supreme Court after the president had tried to extend his four-year term in office illegally.
State TV showed images of a march by several thousand anti-Zelaya protesters, many wearing the national colours of blue and white, who took to the streets in the main industrial city of San Pedro Sula.
The broadcaster ignored a pro-Zelaya protest of roughly the same size in the capital, Tegucigalpa.
"OAS: We want democracy, not Chavez," one banner read at the rally against Mr. Zelaya, who was unpopular with many in Honduras, particularly the country's wealthier conservative elite, for his alliance with Venezuela's socialist President Hugo Chavez.
Many Hondurans struggle to understand why foreign leaders, from U.S. President Barack Obama to most of Latin America's presidents, have backed Mr. Zelaya.
"They have only listened to (Mr. Zelaya) abroad, they haven't listened to the population. But that doesn't matter. We will continue alone," said Adela Guevara, a hotel worker.
Mr. Zelaya's popularity had dipped to around 30 per cent in polls in recent months as he pushed for a referendum to extend presidents' term limits in Honduras, an impoverished coffee and textile exporter of some 7 million people.
Since his ouster Mr. Zelaya has said he plans to return home as president, but only to serve out the rest of his term, which ends in 2010. The interim government has said he will be arrested if he tries to come home.
The European Union has condemned the coup and EU president Sweden said all the ambassadors from the 27-nation bloc had left Honduras.
The interim government told Reuters on Wednesday that there was "no chance at all" of Mr. Zelaya returning to office.
The Honduran Congress approved a decree on Wednesday to crack down on opposition during a nightly curfew imposed after the coup. The decree allows security forces to hold suspects for more than 24 hours without charge and formalizes the prohibition of the right to free association at night.