The White House sharply criticized a US senator’s trip to Syria as "not helpful" and "not appropriate" and warned Damascus not to see the visit as an indirect overture from Washington.

"Even lending a further specter of legitimacy to that government undermines the cause of democracy in the region," spokesman Tony Snow said after Democratic Senator Bill Nelson met with Syrian President Bashar al-Assad.

"We do have diplomatic relations with the Syrians. And they do know what our position is. And that position is not going to change," he said. "The president is in charge of foreign policy. It may cost some people their credibility."

The Iraq Study Group led by former secretary of state James Baker recently urged US President George W. Bush to engage Tehran and Damascus in an effort to secure their help in quelling violence tearing Iraq apart.

On Thursday, Democratic Senator John Kerry, Bush’s 2004 rival for the White House, lent qualified support to that suggestion, saying during a visit to Cairo: "I think it’s important to begin a discussion."

"I think it’s important to talk, to have dialogue, but you don’t give up your principles and you don’t make deals that are against your larger interest," Kerry said after meeting Egyptian President Hosni Mubarak.

The White House, however, took a dim view of the suggestion.

"The Syrians have been adventurous and meddlesome in Iraq, and in Lebanon, and working against the causes of democracy in both of those countries," Snow said. "It’s absolutely vital that the democracies succeed in both places."

"And therefore, the Syrians should have absolutely no doubt that the position of the United States government is the same as it has been," he said.

"They need to stop harboring terrorists. They need to stop supporting terrorism in Iraq, Lebanon and elsewhere. They need to stop serving as headquarters for terrorist organizations. And they need to demonstrate goodwill," he said.

Nelson said Thursday he had had a "sharp disagreement" with Assad over UN-endorsed plans for an international tribunal into the February 2005 murder of Lebanese ex-premier Rafiq Hariri.

The senator from Florida, a member of the Senate Foreign Relations Committee, is the first US lawmaker to visit Damascus since January 2005. Fellow Democrat Chris Dodd is to travel to Damascus later in the week.

In a statement, Dodd said US lawmakers "need to go to hotspots not just garden spots. I cant think of a more critical part of the world than the Middle East, and I cant think of a more critical player in effecting events in the region for good or for bad than Syria."

"That is why I have decided to include a stop in Syria during my seven day fact finding trip to the region," Dodd said.

Snow dismissed such arguments.

"A lot of times a member of Congress may think, ‘Well, I’m going to go there, and I’m going to tell them. I’m going to tell them exactly the same thing. I’m going to take a tough line,’" said the spokesman.

"You can take a tough line all you want, but the Syrians have already won a PR (public relations) victory. And so it’s important to realize that in this case, it is not that there is a want of communication," he added.

Copyright © 2006 Agence France Presse