US defence chief Donald Rumsfeld played down rebel resistance against coalition forces in Iraq today, despite several days of serious violence.
He discounted the strength of radical Shia cleric Muqtada Sadr's force, which is thought to have been swelled by disgruntled, unemployed young men to about 3,000 fighters.
Speaking in Washington, the US defence secretary said: "The number of people involved in those battles is relatively small.
"There's nothing like an army or large elements of people trying to change the situation. You have a small number of terrorists and militias coupled with some protests."
Mr Rumsfeld said some American troops due to leave Iraq soon might have to stay longer, although the commander of American forces in the region, Gen John Abizaid, and his deputies had not asked yet for more troops or an order delaying the departure of any soldiers.
"You can be certain that if they want more troops, we will sign deployment orders so that they'll have the troops they need," Mr Rumsfeld said at the Pentagon.
Delaying the departure of existing troops would give the US the advantage of thousands of extra forces to deal with the upsurge in unrest.
Mr Rumsfeld said: "We're taking advantage of that increase, and we will likely be managing the pace of the redeployments to allow those seasoned troops with experience and relationships with the local populations to see the current situation through."
His comments follow calls this week for an increased international military presence to clamp down on the bloody unrest in Iraq which has left at least 30 coalition troops and 150 Iraqis dead since the weekend.
Mr Rumsfeld spoke ahead of crisis talks next week between Tony Blair, George Bush and the UN Secretary General Kofi Annan.
Downing Street said the talks next Thursday and Friday would cover Iraq, the Middle East peace process, weapons proliferation and the fight against terrorism.
Mr Blair will have dinner with Mr Annan in New York next Thursday to discuss the UN's role in the run-up to the planned handover of sovereignty to an Iraqi-led administration at the end of June.
US commanders have promised to "destroy" the army of al-Sadr which has been waging extensive fighting across the country after he called for the majority Shia population to rise up against occupying forces.
The US military's deputy head of operations, Brigadier General Mark Kimmitt, said US forces were trying to hunt down members of his al-Mahdi Army in Baghdad's Sadr City, and called on al-Sadr to surrender.
"The coalition and Iraqi security forces will continue deliberate, precise and powerful offensive operations to destroy the al-Mahdi Army throughout Iraq," said Brig Gen Kimmitt yesterday.
Meanwhile, President Bush insisted the US would not waiver, saying: "Our resolve is firm... and we will prevail."
General Richard Myers, chairman of the Joint Chiefs of Staff, said today the fighting came in two broad categories.
West of Baghdad in cities such as Ramadi and Fallujah, the main opposition was "former regime loyalists", including supporters of former president Saddam Hussein and anti-American foreign fighters loyal to Abu Musab al-Zarqawi, a Jordanian-born terrorist believed to be linked to al Qaida, he said.
Militiamen loyal to al-Sadr clashed with Polish troops in the holy city of Karbala yesterday and Ukrainian forces were forced to evacuate the city of Kut, south west of Baghdad, during clashes with the cleric's army. At least 12 Iraqis were reported killed and 20 wounded.
There were also signs of sympathy for the al-Sadr revolt by the Sunni rebels as graffiti praising his "valiant uprising" appeared on mosque and government building walls in the Sunni city of Ramadi.
Al-Sadr said Iraq would become "another Vietnam" for the United States unless it transferred power to Iraqis not connected with the US-led occupation authority.
"I call upon the American people to stand beside their brethren, the Iraqi people, who are suffering an injustice by your rulers and the occupying army, to help them in the transfer of power to honest Iraqis," al-Sadr said in a statement from his office in the southern city of Najaf.
There have also been peaceful protests supporting al-Sadr in the northern cities of Mosul and Rashad.