Philippines President Ferdinand E. Marcos said today he will seek a clearer pledge from President Jimmy Carter and the new U.S. Congress for the defense of the Philippines from attack as part of a new bases agreement.

Marcos indicated, however, that he was willing to give Carter plenty of time to work out his policy toward future U.S. use of the huge Clark Air Base and Subic Naval Base north of here. "I don't think it's seemly for the Philippines to rush in when the President is barely getting acquainted with his new home," Marcos said in an interview.

Marcos' renewed emphasis on the need for strong defense commitments from Washington comes after negotiations over the bases broke down in December. A tentative pact apparently fell through when Marcos insisted that U.S. payment for the bases be considered rent, rather than military and economic aid subject to reductions by Congress.

Sources close to Marcos say he is concerned about what military support he might expect from the U.S. forces at the two bases if potentially oil-rich islands in the Spratley chain claimed by Manila were attacked by a neighboring power such as Vietnam. Up to now, Washington has declined to take sides in the dispute among the Philippines, Vietnam and China over ownership of several South China Sea islands.

The existing U.S. Philippines mutual defense pact says that Washington will act in event of an attack on tht Philippines "in accordance with its constitutional processes." "We want to know exactly what that means," Marcos said. "Does that mean that if we are under attack . . . there would be a long delay before ay succor, any help would come to the Philippines, as happened in the case of the fighting in Bataan?"

The reference to the U.S. decision to abandon the Philippines to the Japanese at the beginning of World War II reflects one of the more bitter memories Filipinos have of their long relationship as a former colony and commonwealth of the United States.

Marcos has threatened as recently as Jan. 8 to break all military ties with the United States. Today he softened the threat a bit, saying he was hearing conflicting arguments from his advisers.

"There are those who propose that the bases be terminated because they are merely an attraction to a pre-emptive nuclear strike on the perimeter of the defenses of the United States," he said. "And there are those who of course propose we should anticipate not a nuclear was but a conventional war, in which case the bases would be valuable."

Marcos said he did not know when the Carter administration wanted to resume the bases talks. He denied rumors that he was planning to bring the ambassador to Washington Eduardo Romualdez back to a Manila Cabinet post an dreplace him with the former presidential executive secretary Alejandro Melchor, who was a midshipman with Carter at Annapolis.

U.S. officials have tended to write off Marcos' threats to close the bases as a negotiating ploy to win a bigger annual payment or at least to keep Washington's attention from wandering to more troublesome parts of the would. Marcos today said he expected the U.S. side to take such an attitude "as part of the negotiations," but added that "the hardheaded realization that the world has changed should come to the United States now and to the leadership of the United States."

Both sides seemed in agreement in December on a U.S. payment of $1 billion to the Philippines over five years, about twice what Washington pays now, U.S. military officers continue to object to paying the money as rent when they consider the bases as an aid to the defense of the Philippines. There is less sympathy for the Pentagon's view on this matter in the State Department and the Congress, however.

Marcos' insistence on a stricter definition of the U.S. defense commitment still presents a problem, since the Congress and the State Department have shied away from such commitments that could bring on another Vietnam-type involvement.

There has also been some debate within the U.S. government over the usefulness of the Philippines bases, the last major U.S. military installations in Southeast Asia, Subic remains an important fueling and repair shop, but since the fall of Vietnam Clark has been described by one senator as a "base in search of a mission." Some diplomats have scoffed at new efforts to describe it as an important backup to U.S. forces in the Indian Ocean, or even the Middle East.