President Bush has welcomed the news that seven Americans held as prisoners of war in Iraq are free and well. At the same time, he is urging Syria once again to cooperate with the United States and close its doors to fleeing Iraqi leaders.

President Bush has been careful to respond to recent events in Iraq in a restrained fashion, keeping his personal feelings in check. But there was no missing the smile on his face when he talked about the former prisoners of war.

"Seven Americans are alive! Seven people who were missing are now alive!," he said.

And yet, the president also made clear there is a lot of unfinished business in Iraq. He said, while rejoicing for those freed, the American people are still praying for others whose whereabouts remain unknown.

"We still have missing in action in Iraq. We will continue to look for them. We pray that they too will be safe and free," he said.

Mr. Bush spoke to reporters just moments after he returned to the White House from Camp David, the presidential retreat in the mountains of nearby Maryland.

The first question posed dealt with Syria, and concerns it might become a haven for fleeing Iraqi leaders. When asked about possible military action against Damascus, the president spoke instead about the need for Syrian co-operation.

"The Syrian government needs to co-operate with the United States and our coalition partners, and not harbor any Baathists, any military officials, any people who need to be held to account for their tenure," he said.

Mr. Bush also contended that Syria has chemical weapons, a charge made before by U.S. intelligence officials. During an appearance on American television, a top Syrian diplomat denied both accusations. Imad Moustapha, Syria's deputy ambassador to the United States, told NBC's Meet the Press his country would open its doors to weapons inspectors, and wants to see them at work throughout the Middle East.

"Syria is not only accepting, it is warmly welcoming, it is our desire, it is our wish. Please help us free this region from all weapons of mass destruction," he said.

The Syrian official went on to urge U.S. troops to monitor Iraq's border with Syria. President Bush, while not responding to the request, said the security situation in Iraq is improving. Mr. Bush said Saddam Hussein created the conditions for chaos because he ruled through fear, and though it will take time, the Iraqi people will have stability.