Vietnam's published version of Richard M. Nixon's promise of billions of U.S. postwar aid omits the single paragraph which notes that the U.S. Congress would have to approve any such aid.

State Department officials said yesterday that the paragraph was transmitted to Hanoi according to their records. They added that then-national security adviser Henry A. Kissinger also orally informed the Vietnamese on several occasions of Congress' constitutionally mandated role.

An uncompromising Vietnamese commentary broadcast with the rest of Hanoi's documents Sunday said the United States must fulfill "what it has signed and pledged."

The United States "cannot cite contradictions between the executive and legislative branches or the lack of approval by the legislative branch as an excuse for denying its commitments in foreign relations," Hanoi said.

Hanoi's tone indicated that te second session of Carter administration talks with Vietnam on ways to normalize relations will be difficult.

Assistand Secretary of State Richard C. Holbrooke will lead the U.S. delegation to the talks which will begin in Paris June 2, the State Department announced yesterday.

Vietnam continues to link normalization of diplomatic relations with U.S. aid. President Carter has said the United States will not provide aid as a precondition to normalization.

Nixon's Feb 1, 1973, message promised about $3.25 billion in grant aid over five years and between $1 billion and $1.5 billion in other aid.

It was kept secret at the time and the full text was not published until the State Department declassified it last week after prodding by Rep. Lester L. Wolff (D.N.Y.)

Wolff said yesterday that Vietnam's omission of the paragraph noting that congressional approval was required "underscores my intention to pursue this matter with Kissinger and (former Secretary of State William P.) Rogers so we can find out just what was sent, and what was not."

The paragraph was on a separate piece of paper. However, Vietnam did publish a second paragraph that appeared on a sheet after the Congress paragraph.

Vietnam also broadcast Premier Pham Van Dong's Feb. 23, 1973, reply to Nixon confirming the promises of aid and guarding against inflation by stipulating that it should be "at the value of the dollar on Feb. 1, 1973."