Rival parties in the Honduran political crisis on Sunday were to debate a proposal that would return ousted leader Manuel Zelaya as head of an interim "reconciliation" government.

Costa Rican President Oscar Arias, who is mediating talks here aimed at resolving the three-week-old Honduran crisis, told reporters that the negotiations -- which got under way on Saturday -- would resume Sunday at 11:00 am (1700 GMT).

The Costa Rican leader proposed during a marathon session that Zelaya -- tossed out by his own troops in a coup -- return to the country under the terms of a national reconciliation plan, but urged a delay of the move at least until next Friday.

Zelaya has accepted the delay, according to his spokeswoman.

Arias, a Nobel Peace Prize winner, made the suggestion to representatives of Zelaya and de facto Honduran president Roberto Micheletti, whose interim government is under intense international pressure to resolve the crisis prompted by the first Central American coup since the Cold War.

No agreement was reached Saturday on the pivotal issue of whether Zelaya would return to the presidency, but Arias said the two sides would meet again Sunday after attending mass.

The seven-point proposal envisions Zelaya's return to power at the head of a government of "unity and national reconciliation," and the declaration of a general amnesty absolving those who participated in and opposed his June 28 ouster.

The Arias proposal would also see presidential elections moved up to November, with control of the army transferred to the Supreme Electoral Tribunal one month before so military forces could "guarantee a transparent and smooth voting process."

But Micheletti has repeatedly expressed his strong opposition to Zelaya's return or the possibility of the deposed leader serving out the remainder of his term until January 27, 2010.

And his deputy foreign minister, Martha Lorena Alvarado, reiterated in Tegucigalpa that the return of the ousted president would be "very difficult."

However, the top Micheletti envoy in Costa Rica, Carlos Lopez, promised to "thoroughly examine" the Arias plan.

Arias's proposal would also require Zelaya to "expressly renounce" plans to hold consultative votes seeking to gain support for constitutional changes to terms limits.

His attempts to shore up support for changes to the constitution was the precipitating factor in his arrest and expulsion from Honduras by the country's military last month.

The Costa Rican leader acknowledged that "many differences" continued to keep the sides apart and that the parties will have to show "flexibility to bring themselves closer" to agreement.

A diplomatic source told AFP the delegations continue to remain apart on the issue of Zelaya's return.

US officials have already warned that any attempt to return could jeopardize negotiations between his and Micheletti's representatives.

"Tensions are very high," US State Department spokesman Robert Wood said in Washington.

Zelaya tried two weeks ago to enter Honduras on a Venezuelan jet but was prevented from landing at the main airport by Honduran military vehicles parked on the runway.

Zelaya's strongest ally, Venezuelan President Hugo Chavez, said the ousted head of state will be restored to power.

"Zelaya is going to enter Honduras, let's see what those thugs do," Chavez said, referring to the Micheletti government.

Rumors have swirled that Zelaya might try to cross over into Honduras by land from Nicaragua, possibly with Venezuelan or Nicaraguan military units.

But Rixi Moncada, a spokeswoman for Zelaya, said he had accepted Arias's plea for a delay.

"We have accepted Friday, July 24 as the day when Zelaya should return to the republic," Moncada said.

Meanwhile, protestors in Tegucigalpa blocked roads Saturday, including some around the capital. Some 2,000 filled a southern boulevard, yelling "What's our president's name? Manuel Zelaya!"

In the north, altercations between opposing groups of demonstrators resulted in violence that left several protestors with minor injuries.