US President George W Bush on Sunday faced a new clash with congressional Democrats over the unpopular war in Iraq as Senate Democrats reportedly reached a deal that would allow soldiers to spend more time at home.

“If we were to be driven out of Iraq, extremists of all strains would be emboldened,” Bush said yesterday in his weekly radio address.

“Al-Qaeda could find new recruits and new sanctuaries,” he added, naming the extremist network that he blames, along with Iran, for fueling violence in Iraq.

“By contrast, a free Iraq will deny al-Qaeda a safe haven. It will counter the destructive ambitions of Iran. And it will serve as a partner in the fight against terrorism,” he said.

Meanwhile in Washington, thousands of protesters marched from the White House to Congress yesterday, waving placards demanding an end to the war in Iraq, the return of US troops, and the impeachment of Bush.

Organisers said 197 people, including dozens of veterans and activists, were arrested as they crossed police lines.

Police put the number of arrests at 189. Authorities also used pepper spray to disperse the crowd, according to the Act Now to Stop War End Racism (ANSWER) coalition, the group that organized the march.

The president announced in a speech on Thursday that the size of the US force in Iraq would decrease by about 21500 combat troops by mid-2008, with the first 5,700 soldiers leaving Iraq in December. Most of those soldiers had been scheduled to rotate back to the US at that time.