Secretary of State Cyrus Vance said tonight he had been assured by South Korean leaders that the armed forces here support civilian rule in the aftermath of President Park Chung Hee's assassination.

His statement came after meeting with two civilian members of an interim government which includes three military leaders and which has appeared to be the government body since Park's murder eight days ago.

This statement by Vance, read to reporters here shortly before he left the country, did not elaborate on his talks and he refused to accept questions.

It underscored the uncertainty here over the question of who is running the government -- surviving civilian leaders or the generals who take part in the daily meetings.

The country has been under martial law since Park's death. As far as outsiders can determine, daily decisions are being made at meetings of an acting president, two generals, the defense minister and four or five other Cabinet ministers. The armed forces clearly have gained in influence since the assassination, but how much and whether they intend to relinquish it are two unanswered questions.

There has been no public indication when martial law will be lifted or what will happen if it is. Under the present constitution, an election is supposed to be held within three months to fill Park's unexpired term.

Vance said that the country's decision to proceed "along constitutional lines and under civilian authority promises well for the future."

He met for brief periods today with the acting president, Choi Kyu Hah, and with the foreign minister, Park Ton Jin, and reconfirmed with them the U.S. commitment to the country's security.

"They in turn assured me that the armed forces of the Republic of Korea support the present civilian government and will defend their country against any outside interference," he said.

It was not known whether Vance met with Gen. Chung Sung Wha, the Army chief of staff and martial law commander who is now regarded as the strongest single leader in the country's day-to-day affairs.

Chung commands the Army and his subordinates control what is left of the Korean Central Intelligence Agency, whose former director, Kim Jae Kyu, is accused of having assassinated Park in a KCIA dining room.

Gen. Chung, in his only important public statement since the murder and the assumption of martial law powers, has urged people to rally to the support of the support of the martial law command that he heads.

In the blackout of solid information, questions are being asked about how long the military expects to continue exerting its authority.

There was no indication tonight whether Vance had brought up two other sensitive questions -- the future of the present constitution, which Park imposed, and the emergency decrees that Park's administration used to jail critics.

U.S. officials had said on Vance's arrival that he intended to make only general comments on future political reform. Before Park's death, dissidents and the political opposition had sought American influence in forcing the government to abandon both the old constitution and Park's presidential decrees.

Vance said he is confident that a new government can "move forward in a manner that will enjoy broad support among the Korean people and in the world. mWe know that the days ahead will test the nation. But I am confident that the Korean people, in a spirit of conciliation and moderation, will work together as they shape a secure, stable and prosperous future."

The late president was buried today after a state funeral that brought missions from 40 countries. An estimated 2 million people, many of them weeping silently or sobbing loudly, lined the streets of downtown Seoul as the funeral cortege moved slowly past.

He was buried in the national cemetery beside the grave of his wife, who was assassinated by a gunman during a public ceremony here in 1974.