A summit of Arab foreign ministers has demanded the immediate and unconditional withdrawal of US and British forces from Iraq.
The Arab League ministers meeting in Cairo passed a resolution declaring the war on Iraq a "violation of the
United Nations Charter" and a "threat to world peace".
Iraq won wide support
The resolution was adopted unanimously by the 22-member League except for key US ally Kuwait amid heated rhetoric, with Libya hailing "Iraqi heroism".
Syria, which represents Arab states on the current UN Security Council, said it would call for an emergency meeting of the body.
The BBC's Mark Doyle, who was at the summit, says Iraq is likely to be pleased with the outcome, but it is not clear what it means in practical terms.
The League does not have executive powers to implement its resolutions, so there is no mechanism for stopping those Arab states which have US forces on their land - such as Kuwait, Qatar and Bahrain - from continuing to help them.
In New York, the Syrian ambassador to the UN, Mikhail Wehbe, said he would be calling for an emergency meeting of the Security Council to "stop the aggression against Iraq and the Iraqi
people and to withdraw the foreign troops".
The Arab world has been split over what to do about the Iraqi crisis.
Although public opinion in most Arab countries is strongly opposed to the American-led attack, some Arab governments are opposed, openly or in private, to Saddam Hussein.
Libya's representative, Ali al-Treiki, told the Cairo summit that other Arab states would "fall" if Iraq was defeated.
"We have to raise our heads high and salute Iraqi heroism as proof that Arab individuals are capable of confronting
the mighty, the coercive and the arrogant," he said during the four-hour meeting.
Iraqi Foreign Minister Naji Sabri, also in Cairo, predicted the Americans would be forced to retreat.
"We are beating the enemy and the enemy will be beaten and will be buried in the deserts of Iraq," he said, adding that Iraq would continue to aim missiles at US military bases in Kuwait.
He also said that Arab states had an obligation not to allow their territory to be used for launching attacks on Iraq.
Kuwait objected to the resolution passed on Monday after the rejection of a resolution of its own condemning Iraqi missile attacks on its territory.