BEIRUT, Lebanon, AP -U.N. investigators want to question Syria’s president and foreign minister about the assassination of a former Lebanese leader and have made a request to that effect, a spokeswoman for the probe said Monday.

Nasra Hassan, who speaks for a U.N. commission heading the inquiry, also said investigators want to interview former Syrian Vice President Abdul-Halim Khaddam “as soon as possible.”

Khaddam alleged in a television interview broadcast Friday from Paris that the Syrian president had threatened former Lebanese Prime Minister Rafik Hariri several months before Hariri was assassinated in a Feb. 14 truck bombing.

“The U.N. commission has already sent a request to interview Syrian President Bashar Assad and Foreign Minister Farouk al-Sharaa, among others,” Hassan told The Associated Press.

“The commission is waiting for a response from the Syrians,” she said. She refused to say when the request was made.

There was no immediate Syrian government comment on the request, the first time the probe has touched directly on the president.

The commission has said several people whom Hariri spoke to after he met Assad in August 2004 said he told them the Syrian leader had threatened him over his opposition to extending the term of Lebanon’s pro-Syrian president.

Syrian officials, including Foreign Minister Farouk al-Sharaa, have denied any threat was made.

But after Khaddam’s interview, Syria’s ruling Baath Party stripped him of membership and joined parliament in demanding his trial on a charge of high treason, the official news agency SANA reported Sunday.

While Khaddam, who is in France, said Friday that he planned to return to Syria with his family to write a book, it was unclear if he would go back facing a treason charge. Conviction would bring the death penalty.

“Khaddam has joined the band of enemies who are targeting the country and its attitudes,” the Baath Party said in a statement. “Khaddam has betrayed the party, the country and the (Arab) nation. The National Leadership has decided to dismiss Khaddam from the party and put him on trial.”

In two interim reports published late last year, the commission accused Syrian and Lebanese intelligence officials of being involved in the killing of Hariri. In an interview with the media, the outgoing commission chairman, Detlev Mehlis, has said Syrian “authorities were behind the assassination.

Syria has repeatedly denied the charge and tried to discredit those who testified to the commission.

The assassination of Hariri, in a blast that killed 20 other people in central Beirut, was a turning point in modern Lebanese history.

As he was seen as a quiet opponent of Syrian influence in Lebanon, his killing provoked mass demonstrations against Syria. Combined with international pressure on Syria, these protests forced Syria to withdraw its troops from Lebanon in April, ending a 29-year military presence in the country.

But the bombings targeting anti-Syrian figures have continued, with at least 14 attacks on prominent Lebanese since the death of Hariri. Lebanon has asked the United Nations to investigate those as well but the world body has declined.