Manuel Zelaya and rival Roberto Micheletti accept mediation by Costa Rican president

The exiled president of Honduras and the coup leaders who ousted him have agreed to US-sponsored talks to try to resolve central America’s worst crisis in a decade.

Manuel Zelaya, who was toppled 10 days ago, and Roberto Micheletti, head of the interim government that replaced him, said on Tuesday they would accept mediation by Oscar Arias, the Costa Rican president who won a Nobel prize for helping to end regional conflicts in the 1980s.

The US secretary of state, Hillary Clinton, announced the initiative after meeting Zelaya in Washington, the Obama administration’s first centre-stage foray into the crisis.

“We call upon all parties to refrain from acts of violence and to seek a peaceful, constitutional and lasting solution to the serious divisions in Honduras through dialogue,” said Clinton.

Zelaya and Micheletti, each boasting vocal supporters in their bitterly divided country, are due to meet Arias on Thursday in the Costa Rican capital San José.

An imminent breakthrough seemed unlikely. Zelaya said his return to power was non-negotiable – a demand flatly rejected by Micheletti.

Arias said the fact that the two rivals agreed to talks was promising. “What is important is there is a willingness by both sides to sit down and negotiate,” he said.

Zelaya, a cattle rancher turned leftist ally of Venezuela’s president Hugo Chávez, is popular with the poor for social programmes and rhetorical attacks on the oligarchy.

But he lost the support of congress, the army, the supreme court and his own party. They accused him of authoritarianism and trying to perpetuate himself in power. Soldiers seized him in his pyjamas on 28 June and bundled him into exile.

The de facto government said its takeover was constitutional but the international community united in condemnation, leaving the impoverished coffee-exporting country politically isolated and economically vulnerable. Peaceful demonstrations for and against Zelaya were held in Tegucigalpa on Tuesday.

Zelaya told Honduran radio his reinstatement was “non-negotiable” and that the point of the talks would be to arrange “the exit of the coup leaders”.

Micheletti repeated that Zelaya would face charges of treason and corruption if he returned. “We are going to dialogue, not negotiate the return of ex-president Zelaya, who can only come back if it’s to face trial.”

Zelaya tried to return on a Venezuelan jet last Sunday but military vehicles parked on the airport runway at Tegucigalpa, forcing his flight to divert to Nicaragua. Soldiers opened fire on the leftist’s supporters massed outside the airport, killing at least one and wounding dozens.

The US condemned the coup and the army violence but finessed its calls for the return to power of a leader who tilted Honduras away from its traditional pro-Washington stance and towards Chávez’s brand of anti-imperialist rhetoric.

Barrack Obama, speaking in Moscow, said the US supported “the principle that people should choose their own leaders, whether they are leaders we agree with or not”.