ABU DHABI, United Arab Emirates (AP) _ A newspaper claimed Monday to have interviewed Abu Nidal and said the Palestinian terrorist had undergone plastic surgery and has sneaked into the United States on a false passport.

The Abu Dhabi newspaper al-Wahda said Abu Nidal, code name for Sabry al- Banna, took responsibility for the Dec. 27 terrorist attacks in Rome and Vienna airports in which 19 people, including 5 Americans, were killed and about 120 injured.

He promised more attacks on Americans, praised Libyan leader Col. Moammar Khadafy as an ''honest man,'' and said British Prime Minister Margaret Thatcher was prominent among the names on his assassination list, the newspaper said.

The independent al-Wahda claimed Abu Nidal was interviewed last Wednesday in an undisclosed Middle Eastern capital by the paper's east Mediterranean correspondent, who it said is based in Amman, Jordan.

In Abu Dhabi, officials of the Palestine Liberation Organization, which has sentenced Abu Nidal to death in absentia, dismissed the interview as ''sheer fabrication.'' The PLO officials spoke on condition of anonymity.

Al-Wahda stressed that Abu Nidal was ''alive and has not died as was alleged by the British television in 1984.''

There have been several reports in the past two years that Abu Nidal had died or was seriously ill. A few European newspapers subsequently published what they said were interviews with him, but there has been no independent verification that the man interviewed was indeed the mysterious guerrilla leader.

''Actually, at the time when (President Ronald) Reagan was declaring him an outlaw, Abu Nidal was in the United States on a private visit, using false travel documents,'' al-Wahda claimed.

''Abu Nidal has been moving freely all over the world, on the strength of eight (false) passports issued by a number of African and Arab countries.

''What also helped Abu Nidal to move freely even to the United States is a plastic surgery, which was so perfect that his own wife had failed to identify him until she had him talk,'' the paper said.

Abu Nidal was quoted by the newspaper as saying: ''Yes, our group carried out the operations at the Rome and Vienna airports, in addition to a number of commando operations in Spain and the rest of Europe.''

Al-Wahda quoted Abu Nidal as claiming that he went to the United States for an open heart surgery in 1977, when he traveled on a ''counterfeit passport bearing the name of a prominent Arab official.''

The daily newspaper quoted Abu Nidal as stressing ''whenever we are able to hurt Americans we will not hesitate to do so. It's the U.S. assistance that feeds the Zionist entity (Israel). Without this aid the Zionist ghost would cease to exist.''

Abu Nidal also was quoted as saying that Mrs. Thatcher ''is one of the main names on my assassination list, because of her pro-Zionist bias against the Arabs.''

On Khadafy, Abu Nidal was quoted as saying: ''We have a strong and deep friendship with him based on mutual respect, as our dream is identical - Arab unity.''

The United States says it has evidence that Abu Nidal has worked out of Libya.