Assistant Secretary of State Richard Holbrooke said yesterday that last week's House vote prohibiting spending State Department funds on the discussion of aid to Vietnam "is clearly very unhelpful."

In response to a question from House Asian and Pacific Affairs Subcommittee Chairman Lester L. Wolff, Holbrooke said the administration hopes the language of the amendment will be changed in the final bill. Given a rigid interpretation, he said, it could make it impossible for the U.S. negotiators to sit in the same room with Vietnamese negotiators.

Holbrooke led the U.S. side in last week's Paris talks aimed at normalizing relations between the United States and Vietnam.

He will return to Paris for a second round of talks in about two weeks, he told Wolff's subcommittee.

Holbrooke said that he made it clear to Vietnam's negotiator, Phan Hien, that U.S. law prohibits U.S. assistance to Vietnam, and that the Carter administration will not negotiate any secret arrangements with the Vietnamese, but will keep Congress informed.

"It's not the way they've been used to conducting negotiations with our country," Holbrooke said, referring to the secrecy that surrounded every phase of Nixon and Ford administration dealings with Hanoi.

Holbrooke's was the first administration public criticism of the amendment Rep. John Ashbrooke (R-Ohio) offered to the State Department authorization. It was approved after a few minutes of debate, 266 to 131.

The vote reflects the widespread congressional opposition to any U.S. aid to Vietnam.

Holbrooke said the Vietnamese in Paris last week did not ask for a specific dollar figure, but reiterated their position that the United States should make a contribution "to healing the wounds of war."

Neither former President Nixon's 1973 letter pledging $3.25 billion in aid nor Article 21 of the Paris agreement, which calls for postwar aid, was specifically mentioned at last week's seven hours of talks, Holbrooke said.

The Vietnamese asked for indications of what kind of aid might be available. Holbrooke said, and he replied that he could not provide any indications since U.S. law prohibits any such assistance.

The Nixon letter is "ancient history" and it would not be helpful if it were raised at the negotiations, Holbrooke said. Wolff is seeking the release of the Nixon letter and Holbrooke said efforts were being made to release the full text.

The $3.25 billion fiture promised inthe letter and widely mentioned in the media has led to the misapprehension among several Southease Asian governments that the United States is discussing levels of aid for Hanoi that "would radically transform the balance of power in Southeast Asia," Holbrooke said.

The United States last week offered to normalize relations and exchange ambassadors. Once the embassies are in place, Holbrooke said, the United States would drop its trade embargo against Vietnam. In return, Vietnam promised to continue to make efforts to learn more of the fate of the 2,550 U.S. servicemen listed as missing in Indochina.

The United States also informed Vietnam last week that it will drop its opposition to United Nations membership for Vietnam.