General Powell, who met President Assad in Damascus on Saturday, said that the US Administration was monitoring Syria’s moves.

“What I said to him is that we would be watching and we would measure performance over time to see whether Syria is prepared now to move in a new direction in light of these changed circumstances,” he told ABC television.

The key to whether Syria appears to be co-operating will be whether it keeps its eastern border closed and hands over any Iraqi suspects who might cross it to escape prosecution.

“If Syria follows through on those steps and co-operates with rebuilding Iraq, including the formation of a democratic government,” General Powell said, “then that tells us that they are looking for a better relationship with the United States. If they do not, then there will be consequences.”

There were already signs of progress as analysts said that the offices of Hamas, Islamic Jihad and the Popular Front for the Liberation of Palestine General Command may soon close, despite denials by the groups.

However, Hezbollah, the militant Shia movement, dismissed American pressure imposed on its backers, Syria and Lebanon, to disarm it and end its dominance in southern Lebanon. “We are listening (to the threats), we see them carried in the press, but they change nothing for us,” Sheikh Naim Qassem, Hezbollah’s deputy secretary general, said in a statement.

General Powell said that there were many ways to confront a country, including diplomatic, political, economic and military ones. “The President has all of his options on the table,” he said.

However, General Powell and Donald Rumsfeld, the US Defence Secretary, were more reticent on the search for weapons of mass destruction in Iraq. Both played down expectations of an early discovery of biological, chemical or nuclear weapons in Iraq, while insisting that they would be found.

Coalition forces have captured several potential witnesses to Saddam Hussein’s arms programmes, but apparently so far none has co-operated with his interrogators. Mr Rumsfeld said that the United States would have to rely on low-ranking Iraqi officials from Saddam’s regime to disclose the existence of banned weapons.

He held out little hope that the weapons would be found independently. “We’re going to find what we find as a result of talking to people, not simply by going to some site and hoping to discover it,” he said.

On the fate of Saddam, Mr Rumsfeld said that most importantly he was out of power and no longer a threat. “If I had to guess, I would suspect that (Saddam) may very well be alive,” he said.

Most American voters are not pushing for proof of the banned weapons, focusing instead on economic concerns ahead of the presidential elections in November next year, but a failure to find any weapons could be exploited by Democrats in the months ahead.

However, the search for banned weapons should get a boost from an American plan to hand the peacekeeping and humanitarian mission in Iraq to an international force. At first, at least, it will augment rather than replace the 135,000-strong US military force in Iraq, one of whose chief goals is to find and destroy weapons.

Responsibilities are to be split across three zones, with the United States, Britain and Poland each controlling a section. The United States will commit a single division of 20,000 troops to its sector.

Italy, Spain, Ukraine, Denmark, the Netherlands and Bulgaria have committed troops to serve in the other sectors and other countries have offered logistical support.

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