Speaking during a visit by a team from the European Union, Syrian Foreign Minister Farouk al-Shara warned that a US-led attack would bring chaos to the Middle East.
Mr al-Shara also said this would increase violence and terrorism.
The Syrian criticism comes as the US national security advisor, Condoleezza Rice, said Washington expected to administer Iraq for a certain time after Saddam Hussein has been ousted.
Region's fears
Mr al-Shara stressed that the current crisis was between the UN and Iraq, and it was not a matter to be dealt with by Washington alone.
He said that the US itself must abide by the terms of the UN resolution 1441.
That meant, he added, giving the UN weapons inspectors more time to complete their work in Iraq, where they are searching for any weapons of mass destruction.
The BBC's Richard Galpin in Damascus says Syria is desperate to prevent another Gulf War, fearing the political and economic fallout across the entire region.
Our correspondent says it is a view shared by Greece, the current holder of the EU presidency.
Greek Foreign Minister George Papandreou - who is leading the EU team to the Middle East - said it was the UN which should be "in the driving seat" over the Iraqi crisis.
Mr Papandreou added that there was still a chance to find a peaceful solution, but the onus was now on President Saddam to co-operate with the UN and disarm fully.
Despite the open divisions in Europe over the Iraq crisis, Mr Papandreou said he had a clear mandate from EU member states to deliver this message to Arab leaders.
Our correspondent says Greece is hoping that Iraq's neighbours will persuade President Saddam to co-operate with the UN and even persuade him to go into exile.
'After-Saddam' plan
He says the US and its staunchest ally, Britain, appear to be heeding calls from many countries for more time to given to the inspectors, although it is being limited to weeks not months.
On Sunday, Ms Rice said the US military will play a central role in maintaining order in Iraq for an initial period after the ousting of President Saddam.
In an interview to the Egyptian newspaper, al-Ahram, Ms Rice did not say how long that period would last, but suggested it would be at least while military operations continued.
She said the US and its allies would need to prevent the eruption of violence, maintain Iraq's unity and guarantee the distribution of humanitarian aid.
Ms Rice also said Washington was anxious that Iraq should be governed by Iraqis as soon as possible.
But when asked about when she would expect an Iraqi civilian government to be able to take over, she only said it would depend on developments on the ground.
Mr Rice suggested however that it would take some time for Iraqi civilian leaders to emerge.
The BBC's Heba Saleh in Cairo says Arab leaders fear that anything that even remotely resembles a foreign occupation of Iraq would bring further instability to an already turbulent region.