United Nations Secretary-General Kofi Annan said Iraq was in the grip of civil war as the United States and Iraqi forces attacked insurgent bases in a bid to shore up the authority of a government itself driven by factional rivalries.
In Washington, outgoing Defence Secretary Donald Rumsfeld was revealed to have acknowledged in a memo just before he lost his job that US strategy was not working and it might be better to reduce troop numbers.
President George W Bush has repeatedly rejected recent assertions in the mainstream media that Iraq is now embroiled in a civil war.
Annan's remarks, to the BBC, might add to pressure for a swift change of policy.
"When we had the strife in Lebanon and other places, we called that a civil war -- this is much worse," Annan said.
He agreed with Iraqis who said life was worse now than it was under deposed president Saddam Hussein.
"If I were an average Iraqi obviously I would make the same comparison -- that they had a dictator who was brutal but they had their streets, they could go out, their kids could go to school and come back home without a mother or father worrying, 'Am I going to see my child again?" Annan said.
"And the Iraqi government has not been able to bring the violence under control," he added.
In western Anbar province, two US soldiers were killed by a roadside bomb on Saturday and three Marines died from wounds sustained from enemy action, the US military said.
The Rumsfeld memo, written a day before voter dismay over Iraq cost the Republicans control of Congress, said: "It is time for a major adjustment. Clearly, what US forces are currently doing in Iraq is not working well enough or fast enough."
Rumsfeld, a leading planner of the Iraq war, outlined several options but endorsed none.
Among them were reductions in US forces and bases and a recasting of the US goals there. He suggested cutting US bases to just five from 55 by mid-2007.