US President George W. Bush has claimed a war to topple Iraqi President Saddam Hussein will help spread hope and democracy across the Middle East.
Proposing his plans for a post-war Iraq in a televised speech, Mr Bush said the United States would lead in destroying Iraq's suspected chemical and biological weapons, and provide security "against those who try to spread chaos or settle scores, or threaten the territorial integrity of Iraq".
Mr Bush said in case of war, the United States would act quickly to protect Iraq's oil facilities from sabotage.
"We will remain in Iraq as long as necessary, and not a day more," he said. "A liberated Iraq can show the power of freedom to transform that vital region, by bringing hope and progress into the lives of millions".
His speech was partly aimed at answering Arab states and European allies who oppose the prospect of war, fearing it could further destabilise the Middle East.
Leaders of the Arab League's 22 members are to hold a summit at the Egyptian Red Sea resort of Sharm el-Sheikh on Saturday.
League Secretary-General Amr Moussa said there was a general consensus against war, which he said could unleash chaos in the Middle East.
Earlier, the United States said its warplanes on patrol over Iraq had attacked two air defence communications installations in the south, a day after striking what the US military said were missile systems in the north and south.
An Iraqi military spokesman said the Western planes had targeted civilian installations. He did not mention casualties.
In the latest anti-war protest in the United States, hundreds of thousands of people called and faxed US leaders in a "virtual march on Washington" on Wednesday, jamming the White House switchboard and many congressional telephone lines for several hours.