Henry A. Kissinger used his historic meeting with Prime Minister Zhou Enlai of China in 1971 to lay out in detail a radical shift in American policy toward Taiwan in exchange for China's help in ending the war in Vietnam, previously classified documents show.

The account of the meeting in the newly released documents contradicts the one that Mr. Kissinger published in his memoirs.

The documents also indicate that the Nixon administration was determined to withdraw from Vietnam -- even unilaterally, and even if it led to the overthrow of the government of South Vietnam.

The documents, released today by the National Security Archive, an independent research group, include the transcript of the meeting on July 9, 1971, in which Mr. Kissinger, then the national security adviser, pledged that the United States would not support independence for Taiwan.

The two documents were among 41 recently declassified documents released by the private, nonprofit organization relating to communications between the United States and China that led to Mr. Nixon's visit to China 30 years ago this month.

In the first volume of Mr. Kissinger's memoirs, ''The White House Years,'' published in 1979, he gave the impression that the purpose of the crucial meeting was not to allay tension between the two countries on subjects like Taiwan, which China considers a renegade province. Rather, he wrote, it was ''to discuss fundamentals.''

He added, ''Precisely because there was little practical business to be done, the element of confidence had to emerge from conceptual discussions.'' Taiwan, he said, ''was only mentioned briefly'' during the crucial meeting.

The encounter was the first at a high level between the United States and China in almost 20 years and established a relationship of trust that paved the way for President Nixon's historic trip to China in 1972 and the eventual normalization of relations between the two countries.

''The document proves that what Kissinger writes in his memoirs about Taiwan being barely discussed is breathtakingly not true,'' said James Mann, senior writer in residence at the Center for Strategic and International Studies, and author of ''About Face: A History of America's Curious Relationship With China From Nixon to Clinton.''

''In the history of U.S.-China relations, it always flew in the face of logic that Taiwan was not discussed.''

Mr. Kissinger, reached by phone in London, acknowledged that his memoirs could have been interpreted as misleading. ''The way I expressed it was very unfortunate and I regret it,'' he said. ''But we were still recognizing the Taiwan government. We had to get some statements of principle within which we could get into other issues. That was the intention.''

The first third of the meeting was consumed by Taiwan, the documents show.

Mr. Zhou clearly stated that in order for relations to be established between the United States and China, the United States must recognize that China ''is the sole legitimate government in China'' and that Taiwan is ''an inalienable part of Chinese territory that must be restored to the motherland.''

Mr. Kissinger pledged that the United States would withdraw two-thirds of its troops from Taiwan -- all those involved in the Vietnam War -- when the war was over. ''As for the political future of Taiwan,'' Mr. Kissinger said, ''we are not advocating a 'two Chinas' solution or a 'one China, one Taiwan' solution.'' Rather, he said that ''the political evolution is likely to be in the direction which Prime Minister Zhou Enlai indicated."

In another document released today, the transcript of a conversation on April 27, 1971, between Mr. Kissinger and Mr. Nixon, Mr. Kissinger made clear that neither George Bush, then the chief American envoy at the United Nations, nor Governor Nelson A. Rockefeller of New York would be an ideal choice to travel secretly to China to meet Mr. Zhou.

When Mr. Nixon raised the possibility of sending Mr. Rockefeller, Mr. Kissinger said of his former patron, ''He wouldn't be disciplined enough, although he is a possibility.''