Honduras' deposed President Manuel Zelaya and his rival failed to strike a deal on Sunday to solve the country's political crisis after two days of talks, Reuters reported.
Minutes after the talks in Costa Rica collapsed, Zelaya -- who was ousted in a June 28 military coup -- told Reuters that "no one can stop me" from returning to Honduras, a move that Washington has tried to dissuade him from taking due to fears it would trigger violence.
Zelaya's team said it would not continue negotiating with the de facto government that replaced him, but left the door open to further talks in the future.
"This dialogue with this commission of the de facto, military coup government is finished," Rixi Moncada, a Zelaya representative said on Sunday after the talks collapsed in the Costa Rican capital, San Jose.
Costa Rican President Oscar Arias, the mediator in the talks, held out hope for renewing the dialogue but set himself a three-day deadline.
"My conscience tells me that I cannot give up and must continue working for at least three more days and that is what I propose to do," Arias told reporters.
Honduras' interim leader, Roberto Micheletti, flatly rejected Arias' proposal that Zelaya be reinstated, the major stumbling block in the mediation.
"I'm very sorry, but the proposals that you have presented are unacceptable to the constitutional government of Honduras ... in particular your proposal number one," said Carlos Lopez, head of the negotiating team for Micheletti.
Zelaya is in exile in Nicaragua and, like Micheletti, he did not attend the weekend talks in Costa Rica.