Updated

The U.N. commission investigating the assassination of a prominent Lebanese politician has asked to interview Syria's president and foreign minister, the panel's spokeswoman said Monday.

Nasra Hassan also said investigators want to interview former Syrian Vice President Abdul-Halim Khaddam "as soon as possible."

Khaddam alleged in a TV interview broadcast Friday that Syrian President Bashar Assad had threatened former Lebanese Prime Minister Rafik Hariri several months before Hariri was assassinated in a Feb. 14 truck bombing.

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

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

"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 to interview Assad was made.

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 has 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.