Aziz told a new conference further information would be released Wednesday, the British Broadcasting Corp. reported.
In addition, an unnamed senior Iraqi official told BBC that Abu Nidal acted after he was accused of treason against Iraq in contacting Kuwaitis fomenting plots against his host country.
Earlier Tuesday in Beirut, Lebanon, the Fatah-Revolutionary Council said that its leader Abu Nidal, is alive and in good health, denying reports that he was found dead in his apartment in Iraq.
An FRC source in Beirut, who requested anonymity, told United Press International that the report about Abu Nidal's death was "totally untrue" and was "the fabrication of enemy intelligence services."
The source said "Abu Nidal is well and in good health" and still leading "his struggling missions."
"It is not the first and only time that the enemy services try to spread rumors for passing treacherous deals on the Palestinian scene," he said.
The source refused to give details on Abu Nidal's whereabouts but said his group may release more information later.
On Monday, reports circulated that Abu Nidal was found dead a few days ago in Baghdad. Some suggested that he committed suicide when an Iraqi force tried to arrest him.
The London-based Saudi Ash Sharq al Awsat newspaper maintained Tuesday that Abu Nidal was killed Friday by gunmen in a house in Baghdad in which he had been living with four of his followers.
The newspaper quoted an unnamed Palestinian source in the West Bank city of Ramallah as saying that "the gunmen assassinated him after the Iraqi authorities discovered a connection between his group and foreign authorities believed to be Kuwaiti."
The source said Abu Nidal was hit with "four bullets and two of those who were with him in the house were wounded." He said the Iraqi authorities arrested a number of Abu Nidal's followers and were looking for others.
Abu Nidal broke from the mainstream Fatah movement in the 1970s and was blamed for several assassinations and bombings that killed or wounded hundreds of people in various countries. The U.S. State Department has described Abu Nidal's group as the most dangerous in the world.
Abu Nidal founded FRC in 1974 when he was sentenced to death in absentia after he tried to assassinate Palestinian leader Yasser Arafat for moderating his stance toward Israel. Abu Nidal broke with the PLO because of its decision to abandon the struggle to oust the Israeli government and accept a Palestinian state in the Israeli-occupied West Bank and Gaza Strip.
From 1974 to 1980, Abu Nidal moved his group's headquarters to Baghdad where he reportedly received substantial logistic assistance by the Iraqis.
The FRC was considered the most dangerous and active Palestinian organization in the 1980s when it demonstrated an ability to operate over wide areas in the Middle East, Asia, South America and Europe, targeting Palestinians considered to be too moderate as well as Jewish, Israeli and Western interests.
Some 900 people were believed to have been killed or wounded in such attacks in at least 20 countries since 1974.
Abu Nidal was thought to have masterminded the attacks on the Rome and Vienna airports that killed 20 people near the ticket counter of the Israeli airline El Al on Dec. 27, 1985. An Italian court later sentenced Abu Nidal in absentia to life in prison for the Rome attack.
The Abu Nidal group claimed responsibility for the 1985 Egypt Air hijacking, the deadliest in the history of air piracy. That incident ended with a storming of the plane on the island of Malta by Egyptian commandos on Nov. 24, 1985, and the deaths of some 60 people, including all but one of the hijackers.
In the early 1980s, Abu Nidal and his men moved to Syria after they were expelled from Baghdad following disagreements with the Iraqis who started to improve ties with the West during the war with Iran. U.S. pressures on Syria forced the FRC to move its training and operational bases to Lebanon. Abu Nidal was forced to re-locate in Libya after he was expelled from Syria in 1987.
In 1989, Abu Nidal was further isolated when he was accused by some FRC officials who split from the group of murdering 150 militants because of his fear from internal subversion.
Since 1990, FRC's terrorist activities reportedly ceased after the failure of some operations, including the 1988 attack of the Greek cruise ship City of Poros near Athens, and the arrest of most of its militants in South America. The poor health of Abu Nidal, who suffers from cancer, may have also weakened the group.
Abu Nidal, who was born in 1939 in Jaffa, emigrated with his family to Saudi Arabia after the 1967 Arab-Israeli war. He then moved to Egypt where he joined Fatah.
For years, rumors circulated about his whereabouts, health and whether he is alive or dead without confirmation.
(With reporting by Dalal Saud in Beirut, Lebanon.)