President Bashar Assad (search) met with a top U.N. envoy Sunday amid accusations that Syria has not fully withdrawn its intelligence operatives from Lebanon and was perhaps even organizing political assassinations.

U.N. envoy Terje Roed-Larsen (search), who met with Assad for two hours, left the country without commenting on the outcome of the talks. The government also had no comment.

In a statement issued in Beirut, Lebanon, U.N. spokesman Nejib Friji (search) said Roed-Larsen discussed with Assad "all relevant issues and they will continue their dialogue."

Roed-Larsen planned to brief U.N. Secretary-General Kofi Annan (search) on the talks when they meet in Paris on Monday, Roed-Larsen spokesman Fabrice Aidan said. He said there would be no comment on the substance of Roed-Larsen's discussions with Assad until after that meeting took place.

Annan instructed Roed-Larsen last week to leave quickly for Syria to meet Assad about Lebanon without disclosing his mission.

The Bush administration alleged Friday that Syria has not fully withdrawn its intelligence forces from Lebanon despite the pullout of its army six weeks ago and could even be organizing political assassinations.

Syria has denied the allegations as a smear campaign by Washington, saying the reports were a cheap attempt to influence Lebanon's parliamentary elections -- with a third round held Sunday -- and raise provocations against Damascus.

Syria's ambassador to the U.S., Imad Mustafa, told CNN's "Late Edition" on Sunday that Syria had withdrawn from Lebanon "completely and categorically."

He said allegations "that we're going to hit and kill those Lebanese leaders or such things, on the one hand are preposterous."

"But on the other hand, they explain to you what's happening. There are forces that do not want to see a good, friendly, brotherly relation between Syria and Lebanon," Mustafa said. "And they are creating these myth and these stories about Syria going to kill Lebanese leaders.

The Lebanese opposition blames Syria and its Lebanese allies for the murders of former Prime Minister Rafik Hariri and the anti-Syrian journalist Samir Kassir. Both parties deny the allegations.

On Sunday, a Syrian government-run newspaper dismissed the U.S. allegations as "fabricated" and accused Annan of giving in to U.S. pressure.

But what is more surprising, al-Thawra newspaper said, was Annan's "capitulation to the pressures practiced on him as he has started releasing ... baseless hypotheses that lack any credibility."