The chairman of the U.S. Senate Foreign Relations Committee says recent violence in Iraq throws into question the viability of the Bush Administration's planned June 30 deadline for transferring power to an Iraqi-led administration.

Senator Richard Lugar, a key ally of President Bush on foreign affairs, was blunt when asked if the June 30 deadline should be reconsidered in light of continued bloodshed and lawlessness in Iraq.

"It may be," said the Indiana Republican, speaking on ABC's This Week program. "And I think it is time to have that debate, because, clearly, you have the militia that has not been disarmed. If the worst situation comes, the militia begin fighting each other. Then it is civil war. We are in Iraq. So, we are going to have to bring stability, which means disarming the militia, but then carefully training the police."

Senator Lugar's comments followed last week's brutal slaying of four American contract workers in the strife-ridden Iraqi city of Fallujah, regarded as a hotbed of anti-American sentiment.

Earlier, on Fox News Sunday, the ranking Democrat on the Senate Foreign Relations Committee, Joe Biden of Delaware, said the perpetrators of the Fallujah attack had a clear message.

"I am sure the folks in Fallujah who were responsible for this thought that if they were grisly enough they may get a Somalia result, that is America pulling back or pulling out, but the bottom line is that there is no trained Iraqi security forces, not withstanding the talk about having 200,000 trained Iraqis, and we are the game," said Senator Biden. "We are the whole deal. And as long as we are the whole deal, we are going to get the whole brunt of this outrage."

Senator Biden added that it could take as long as three years before Iraq is capable of assuming responsibility for internal security, and that prematurely forcing newly-formed Iraqi units to assume that responsibility would be a recipe for disaster.

But, appearing on the same program, former House Speaker Newt Gingrich said the time has come for Iraqis to become more active in patrolling their country.

"We should insist on shifting more power to the Iraqis," commented Mr. Gingrich. "Of course our enemies are going to do everything they can to stop us. This is a real war. We have real enemies, and they want to kill us. They key to a place like Fallujah is to have Iraqis on the street risking their lives next to Americans and make sure as rapidly as possible that we integrate an Iraqi police, and Iraqi military with the American effort. And having a lot more Americans that do not speak Arabic, do not blend into the population and look even more like an occupying force, I do not think is the answer."

Despite continued violence in Iraq, Mr. Gingrich said he saw no reason to postpone the June 30 deadline for transferring power.