The Honduran government today backed up official U.S. reports that Nicaraguan troops had entered Honduran territory Saturday, but well-placed sources said that fighting between the Nicaraguans and anti-Sandinista rebels was dying down.

"It looks like they the Nicaraguans are in full withdrawal," one of the sources, who declined to be identified, said late this afternoon.

Nicaragua strongly denied that its forces had entered Honduras.

Despite the reported Nicaraguan pullback, U.S. military helicopters were expected to ferry Honduran troops to the border area Wednesday to repell the incursion, the sources said. The U.S. administration offered U.S. helicopters for that purpose today, and granted Honduras $20 million in emergency military aid because of the reported Nicaraguan incursion.

Numerous questions remained unanswered regarding events on the border, and the Honduran government clearly was embarrassed by Washington's efforts to call attention to the reported incursion. The U.S. government has been the only source of information about the incursion, and there was no independent confirmation that it had taken place. The border area is mountainous and isolated and the approximately 6,000 anti-Sandinista rebels, known as contras or counterrevolutionaries, who have bases there, have allowed very few reporters to visit the area.

Late last night, Honduran government spokesman Lisandro Quezada said he had "no knowledge" of the reported incursion and that the reports from Washington "form part of the publicity campaign" by the U.S. administration to win support in Congress for the president's request for $100 million in aid to the contras.

Quezada made the statement immediately after a meeting of Honduras' National Security Council that considered the U.S. reports. U.S. officials said today that after that meeting Honduran President Jose Azcona requested U.S. assistance.

Contra officials were reluctant to discuss reports of the incursions with reporters.

"We can't say anything," spokesman Frank Arana said. "All we can say is that there was an incursion, because the Honduran government issued a communique saying so."

Honduras officially denies that the contras are based in Honduras. Since the Nicaraguan troops reportedly entered Honduras to attack the rebels, it was difficult for the government here to discuss the reports of an incursion publicly.

This morning, however, after consultations with U.S. officials, the Honduran government said formally that there had been "new incursions by the Sandinista Popular Army in Honduran territory."

A five-paragraph communique, issued by Azcona's office, provided very few details and even said that the incursion had taken place in a different province than U.S. officials have said.

The communique said it had ordered Honduran troops to be deployed along the border. It said that Honduras had obtained from the U.S. government "the necessary support for air transportation of the Honduran troops."

Gen. John Galvin, commander-in-chief of the U.S. Southern Command in Panama, arrived here this morning with orders to supervise the expected airlift and otherwise help the Hondurans to repel the Nicaraguans.

In Managua, several Sandinista officials denied the reports and charged that they were part of an attempt to win congresional approval for the $100 million aid request, Washington Post special correspondent Nancy Nusser reported.

"Not in the last week or ever have our troops crossed into Honduran territory to combat the contras," Deputy Defense Minister Joaquin Cuadra said at a press conference.

Cuadra, who is also Army chief of staff, said the Sandinistas have mobilized "a couple thousand" troops into the northern border area to combat a new infiltration of contra forces. He said combat has been heavy in the northern border regions, and since mid-March the contras have made attempts to cross into Nicaragua at 15 points on the border.

Cuadra added that artillery might have been fired across the border in the recent combat, but said no Nicaraguan troops have violated Honduran territory.

According to official U.S. accounts, approximately 1,500 Sandinista troops crossed into Honduras on Saturday in eastern El Paraiso province and moved against two major contra installations. The Sandinista Army forces engaged in heavy fighting with the contras on Sunday and Monday, and penetrated as far as 12 miles into the country, according to the accounts.

The Nicaraguan troops failed to take either of their principal targets, the contras' main base camp and their main training center, according to the well-placed sources here.

The Sandinistas were said to have suffered more than 100 dead and wounded. U.S. officials said the contras suffered 16 dead and 40 wounded.

The Honduran communique did not say when the Nicaraguans had entered Honduras or how many troops were involved. It did not mention the contras at all, and said the incursion had taken place in Olancho province, which is east of El Paraiso.

The communique said the Honduran Foreign Ministry had sent a formal protest to the Nicaraguan government.

The Honduran government appeared to have little information about what was happening along the border, and to have resisted U.S. efforts to use the incident as a means of justifying increased U.S. military aid for Honduras and stepped-up involvement of U.S. forces in providing transportation for Honduran troops.