Pressure from opponents and US builds on Marcos. Holed up in his palace, Marcos imposed a nationwide emergency Monday. Amid reports of a US offer of asylum, the Reagan administration called on Marcos to resign and threatened to stop US aid if he uses force to quash the accelerating rebellion.

Barring an unforeseeable change of circumstances, the regime of President Ferdinand Marcos is living out its last days. At press time Monday, the revolt against his rule had grown both in scope and sophistication, prompting President Marcos to declare a nationwide state of emergency. He later imposed a 6 p.m. to 6 a.m curfew.

His efforts, however, appear to have had little effect: Key troops are showing signs of disobedience and rebels have taken over the main news media. Growing numbers of civilians have poured into the streets in support of the rebellion.

While a combination of rebel military members and spontaneous crowds have been jubilantly dismantling the regime, opposition leader Corazon Aquino has been largely inactive.

In an interview yesterday evening, Juan Ponce Enrile, who resigned as Defense Minister Saturday, said that a provisional government would soon be announced, possibly Tuesday. Mr. Enrile said that the government would initially consist of Mrs. Aquino as President, Salvador Laurel Vice-President, and would include five portfolios. Enrile would retain the defense portfolio and Assemblyman Ramon Mitra would become foreign minister. No names were available for the other portfolios.

About the same time, however, President Marcos reiterated that he had no intention of stepping down or leaving the country.

The state of emergency was declared yesterday morning in an impromptu press conference at the presidential palace of Mala-canang. [Troops guarding the palace fired at a large crowd of demonstrators after firecrackers were set off in a crowd of Aquino supporters, Reuters reports.]

At least eight armored vehicles were dotted through the palace gardens. These included mobile antiaircraft weapons. Nearly all the men present at the press conference -- aides, security officials, even Marcos's son Bongbong -- wore combat fatigues. Some of the military were quietly hostile to correspondents.

During the conference a visibly agitated Gen. Fabian Ver assured the President that his troops were ready to ``destroy'' the rebel forces, which are led by former Defense Minister Juan Ponce Enrile and the deputy chief of staff Lt. Gen. Fidel Ramos.

The measures in the state of emergency announced by Marcos included authorization of military commanders to use small-arms fire -- and larger weapons if necessary -- to suppress the rebel forces. Under emergency provisions, Marcos added, he would require the media to ``check'' with the government to avoid carrying inaccurate reports.

The President found immediate problems in enforcing either instruction. Early Monday morning rebels secured the facilities of the main opposition radio station, Radio Veritas.

About 150 rebel troops then took over the main government radio and TV complex in the capital's northern suburbs. (The TV station went off the air while it was broadcasting Marcos's conference). By late morning the government radio was back on the air -- with a new, pro-opposition slant. The television followed suit in early afternoon.

Events which followed the radio and TV takeover provided a good illustration of how the rebellion has progressed. Immediately after troops took over the area the surrounding streets were packed with rebel supporters. [According to Reuters, one life was lost when a loyalist soldier reportedly shot himself by accident.] People's power, as the rebels call it, took over from fire power. The people milled in the steet, making it difficult for hostile forces to take up position either discreetly or effectively. When pro-government troops did arrive, the people formed barriers, pulling cars across the street and letting the air out of the tires. Then they started to talk to the troops.

The pro-Marcos soldiers committed to the recapture of the radio complex were Scout Rangers from the elite Army second division. The division plays a key role in the political defense of the capital: It is the main source of reserves to Marcos's Presidential Security Command in the event of major disturbances in the city.

The rebels prepared to defend the complex. Then two of their senior officers, Lt. Col. Rudy Aguinaldo and Capt. Phil Plaza announced they would go and talk to the troops. Heavily armed, but with their hands in the air, the two men and a crowd of civilians approached the troops. The two officers said they were also Scout Rangers.

``Look, we have all these people with us. We don't want to fight. Right?'' Colonel Aguinaldo asked. ``The sooner we normalize the situation, the sooner we can reunify the armed forces.''

They shook hands with the troops and embraced some. Civilians who followed pushed soft drinks into the soldiers hands. After the the two officers had worked about 20 troops, a noncommissioned officer gave the order for the rest to form up. They began to move out, surrounded by cheering, applauding crowds. Some of the troops flashed the opposition ``L'' sign with their fingers. Their fighting capacity seemed reduced to nothing.

Scout Rangers from the Second Division are also reported to have been committed to an attack being prepared on rebel headquarters, Camp Crame.

Monday evening, Enrile issued an appeal to the Second Division commander, Brig. Gen. Roland Pattugalan, not to attack his colleagues. Earlier in the day this correspondent spoke to other troops who were being positioned for the attack. They did not seem enthused at the prospect. ``If ordered to proceed to Crame, we shall do so,'' one soldier said. Asked what he would do when he got there, the soldier responded, ``probably nothing.''