The United Nations Secretary-General Kofi Annan today warned the United States not to take unilateral action against Iraq, saying any steps must be sanctioned by the UN Security Council.
"It is extremely important that it should be multilateral, which also means sanctioned by the Security Council," Annan told BBC radio.
"If one does it unilaterally, or with one or two countries, we don't know what happens at the end - the unexpected consequences of this conflict," he said, pointing to fears that a defeated Iraq could splinter and destabilise the region.
US President George W. Bush is due to address the UN General Assembly about Iraq on Thursday, after winning public endorsement at the weekend from British Prime Minister Tony Blair for his determination to deal with Baghdad.
Many other foreign leaders, however, have expressed reservations about any US attack on Iraq to topple President Saddam Hussein and halt Iraq's alleged weapons of mass destruction programme.
Asked if he saw a "chink of light" that Iraq might agree to UN demands for unfettered weapons inspections, Annan said: "We haven't seen it yet, but it cannot be excluded."
Annan, who has repeatedly warned about the consequences of waging a military campaign against Iraq, said the world was already a "messy place" with an ongoing crisis in Afghanistan, potential conflict in Kashmir, violence raging between Israelis and Palestinians and continued wars in Africa.
"On top of all this if we get into a major military operation in Iraq it's going to increase international tensions," he said.
"And I've not even mentioned the economic downturn and the impact this will have on all this as well."
Annan said the need to engage the United Nations in tackling Iraq was crucial to "international legitimacy".
"It's an issue of ensuring there is some order in the difficult world we are living in. If we do not have these rules, the world would be a very difficult place to manage," he said.