In their statement, U.S. Ambassador Zalmay Khalilzad and General George W. Casey condemn the upsurge in car bombings, executions, and retaliatory violence that has claimed hundreds of lives in recent days.
Their statement comes as Abd al-Aziz al-Hakim, one of Iraq's top Shi'ite politicians, is set to meet President George W. Bush in Washington for discuss ways to halt the violence.
It also comes as the Bush administration grapples with domestic pressure to adapt its strategy to counter mounting violence that has threatened to erase gains since the invasion to oust Saddam Hussein in early 2003.
Sectarian violence -- particularly pitting Shi'a against minority Sunnis -- and other attacks have prompted some to describe the bloodshed as a "civil war," a label that the White House has rejected.
Meanwhile, UN Secretary-General Kofi Annan said he believes the situation in Iraq is now worse than what was considered a "civil war" years ago in Lebanon. "A few years ago, when we had the strife in Lebanon and other places, we called that a civil war," he said. "This [in Iraq] is much worse."
Some 50 bodies of people shot to death have been found in and around Baghdad in the past day.
(AP)