Secretary of State Condoleezza Rice praised the work of Syrian security agents in repelling an attack against the U.S. Embassy in Damascus, but said it was too early to say who might have been behind it.

"I think it's very early to try and speculate why this may have happened," said Rice, speaking at a news conference in Nova Scotia Tuesday with her Canadian counterpart, Peter MacKay.

In the past, the Bush administration has been very critical of the tight control that the regime of Syrian President Bashar Assad has over its people. But Rice would not speculate on whether the attack may be an indication that the regime's control is slipping.

In Washington, White House press secretary Tony Snow thanked the Syrian officials who assisted Americans after Islamic militants tried to storm the embassy.

"Syrian officials came to aid of the Americans," Snow told reporters. "The U.S. government is grateful for the assistance the Syrians provided in going after the attackers, and once again, that illustrates the importance of Syria being an important ally in the war on terror."

"It does not mean they are an ally. We are hoping they will become an ally and make the choice of fighting against terrorists," he added.

Snow said the administration does not know who is responsible for the attack.

"They're taking a look," he said. "There have been no claims of responsibility and we have not had an opportunity to dig down and find out. We just don't know."

"It was a serious event and the Syrians did come to our assistance," he said.

Said Rice: "I do think that the Syrians reacted to this attack in a way that helped to secure our people, and we very much appreciate that."

She added that "obviously, we will do the forensics on it and begin to try to get a sense of what happened there."

"It's the case, unfortunately, that it is possible for people to make attacks of this kind despite the fact that we do make an extraordinary effort to protect our people, we make an extraordinary effort to have facilities that are not capable of being attacked," the secretary added.

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