U.S. Secretary of State Hillary Clinton said Tuesday that Costa Rican President Oscar Arias, a Nobel Peace laureate, has agreed to serve as a mediator in the Honduran political crisis. She spoke after a meeting with ousted Honduran President Manuel Zelaya, who she said has accepted the mediation effort, as has the interim government in Honduras.

The Costa Rican president won the Nobel Peace Prize in 1987 for his efforts to broker an end to civil warfare in El Salvador and other Central American states. Clinton, who spoke with Mr. Arias earlier in the day, called him the "natural" person to try to defuse the Honduran crisis.

Clinton met reporters after meeting with ousted Honduran President Manuel Zelaya. It was the highest-level U.S. show of support thus far for Mr. Zelaya, who was toppled in a June 28 coup d'etat that was triggered by his efforts to hold a referendum that could have kept in him office beyond the end of his term in January.

The United States opposed the coup and has refused to recognize the interim government of Roberto Micheletti despite his assertion that Mr. Zelaya was legally removed.

Although the Obama administration has called for Mr. Zelaya's unconditional return to office, Clinton did not repeat that statement in her brief news conference, saying she did not want to prejudge what the parties might agree to in the Arias mediation effort, which she said she hoped would begin immediately.

Mr. Zelaya has threatened to make another attempt to return home, even though a flight carrying him and other Latin American leaders was barred from landing in Tegucigalpa on Sunday.

Clinton made clear she hoped Mr. Zelaya would forgo such an attempt and allow the Costa Rican-based mediation effort to proceed. "We hope at the end of this mediation will be a return of democratic constitutional order that is agreed to by all concerned. The exact nature of that, the specifics of it, we will leave to the parties themselves, as I think now is appropriate. I was heartened that President Zelaya agreed with this. I believe it is a better route for him to follow at this time than to attempt to return in the face of the implacable opposition of the de facto regime. And so instead of another confrontation that might result in a loss of life, let's try the dialogue process," she said.

Zelaya supporters clashed at the Tegucigalpa airport on Sunday with Honduran security forces. At least one person was killed.

Clinton announced the mediation effort as a delegation of Hondurans supporting the Zelaya ouster led by former President Ricardo Maduro were meeting members of the U.S. Congress, some of whom criticize Mr. Zelaya as a disciple of leftist Venezuelan President Hugo Chavez.

Congresswoman Ileana Ros-Lehtinen, ranking Republican on the House of Representatives Foreign Affairs Committee, said Mr. Zelaya had "trampled the law" by seeking to hold an illegal referendum to extend his rule.

But in a speech in Moscow, President Obama again defended the administration's handling of the crisis, saying it opposes extra-legal means of political change.

"America supports now the restoration of the democratically-elected president of Honduras, even though he has strongly opposed American policies. We do so not because we agreed with him; we do so because we respect the universal principle that people should choose their own leaders, whether they are leaders we agree with or not," he said.

Mr. Obama said the United States should not seek to impose a system of government on other countries or presume to try to choose their leaders, adding that Americans "haven't always done what we should have on that front."