TEGUCIGALPA, Honduras - The Americas' top international diplomat flew to Honduras on Friday to give the coup-backed government a firm ultimatum: Restore the president within 24 hours or face crippling sanctions.

The head of the interim government rallied thousands of supporters in front of the national palace and pledged to stand firm in the face of the international pressure.

"I am the president of all Hondurans," Roberto Micheletti proclaimed.

Jose Miguel Insulza, who heads the Organization of American States, was meeting with leaders of Honduras' Supreme Court and Congress -- institutions that approved Sunday's coup -- "basically to clarify exactly what our position is."

That position is that President Manuel Zelaya must be restored to power unconditionally, or Honduras will be suspended from the OAS on Saturday. He admitted his mission was unlikely to succeed: "It will be very hard to turn things around in a couple of days," he said before setting out.

"We are not going to Honduras to negotiate. We are going to Honduras to ask them to change what they have been doing," he said.

Micheletti displayed little intention of ceding to the OAS' demands. He led a raucous chant of "Democracy!" before a giant crowd waving blue-and-white Honduran flags in front of the palace that Micheletti has occupied since Zelaya was seized by soldiers and flown into exile.

"They said we were afraid, but here is the proof that the people are not afraid," Micheletti screamed. "We are asking Hondurans to communicate with their relatives throughout the world to tell them that no coup took place here."

A rival rally by thousands of Zelaya backers marched to the offices of the OAS. Marchers carried a banner with a picture of Zelaya and the words: "Mel our friend, the people are with you!" Labor and farm leaders who back Zelaya said they would meet with Insulza on Friday afternoon.

Despite feared violence, the two groups did not clash. Police helicopters circled overhead and dozens of soldiers and police guarded the palace.

Micheletti's foreign minister, Enrique Ortez, who was designated to meet with visiting OAS officials, said Friday that Insulza "can negotiate all he wants, except for Zelaya's situation."

"That is not negotiable because he cannot return to Honduras, and if he does he will be arrested and tried," Ortez said.

Insulza said he would not meet with members of Micheletti's government to avoid legitimizing it.

Micheletti's supporters say the army was justified in ousting Zelaya -- on orders of Congress and the Supreme Court -- because he had called a referendum which they claim he intended to use to extend his rule. Zelaya denies that and has said he will no longer press for constitutional changes.

Micheletti, who faces almost complete international isolation over his refusal to restore Zelaya, instead offered to move up presidential elections, scheduled for Nov. 29.

Nations around the world have promised to shun Micheletti, who was sworn in after the coup, and the nation already is suffering economic reprisals.

Neighbouring countries have imposed trade blockades, major lenders have cut aid, the Obama administration has halted joint military operations and all European Union ambassadors have abandoned the Honduran capital.

Micheletti's government is so eager to find a friend that it announced it had been recognized by Israel and Italy -- surprising the governments of those countries. Italy withdrew its ambassador to protest the coup, and Israeli Foreign Ministry spokesman Yigal Palmor said: "All rumours about Israeli recognition of the new president are wholly unfounded."

And contrary to Micheletti's assertion, Interpol on Friday released a statement saying it had not received any request to issue an arrest warrant for Zelaya.

Zelaya was in El Salvador on Friday for a meeting with President Mauricio Funes, then flew to an unidentified country. He has said he will return home over the weekend, and Micheletti has vowed to arrest him if he does.

Funes said Zelaya has sworn off any idea of re-election and is willing to drop plans to rewrite the constitution that led to his ouster.

Micheletti asked Nobel Peace laureate Rigoberta Menchu to help mediate the conflict, and she arrived in Tegucigalpa on Friday.

"I come to try to talk with anyone who wants to listen to search for peace for this country," she said.

The OAS says it will suspend Honduras if Zelaya isn't back in office by Saturday. That move could encourage other organizations and countries to suspend international aid and loans to one of the poorest nations in the Western Hemisphere.

Ousted Honduran Finance Minister Rebeca Santos on Friday told international finance ministers in Chile that the coup has already hurt the economy. The World Bank and the Inter-American Development Bank have suspended between $300 million and $450 million in financing.