TEGUCIGALPA– Honduras' de facto government said on Wednesday that talks aimed at ending a deep political crisis following last month's coup have been delayed and it is waiting for new proposals from the mediator.

Carlos Lopez, the interim government's foreign minister, said it remained open to talks but it was not clear when they might begin, and deposed President Manuel Zelaya has vowed to return to Honduras if there is no deal by the end of Wednesday.

I am waiting for a new proposal, Lopez told local television. We are waiting for a call ... Honduras is open to dialogue, he added, saying the talks could resume later this week.

De facto leader Roberto Micheletti, installed by Congress after Zelaya's June 28 ouster, has repeatedly said he would not allow his foe to return to serve out the rest of his term -- the central sticking point in mediation efforts.

But his government has come under intense pressure to back down and accept Zelaya's return under a deal proposed by Costa Rican President Oscar Arias, who is mediating talks.

Arias was expected to make changes to proposals that were rejected by Micheletti over the weekend, but the United States and Latin American leaders are insisting that Zelaya be reinstated.

Honduras' Congress and the state prosecutor's office are set to meet later on Wednesday to discuss and vote on whether Zelaya should be allowed to return and under what circumstances, a senior Congress official said.

Zelaya has called on U.S. President Barack Obama to impose tough new sanctions against those that toppled him.

The coup leaders accused Zelaya of violating the constitution by trying to extend presidential term limits.

(Reporting by Simon Gardner, Gustavo Palencia, Esteban Israel; Editing by Kieran Murray)