WASHINGTON (AFP) - A senior Republican lawmaker said that deteriorating security in Iraq may force the United States to reintroduce the military draft.

"There's not an American ... that doesn't understand what we are engaged in today and what the prospects are for the future," Senator Chuck Hagel told a Senate Foreign Relations Committee hearing on post-occupation Iraq.

"Why shouldn't we ask all of our citizens to bear some responsibility and pay some price?" Hagel said, arguing that restoring compulsory military service would force "our citizens to understand the intensity and depth of challenges we face."

The Nebraska Republican added that a draft, which was ended in the early 1970s, would spread the burden of military service in Iraq more equitably among various social strata.

"Those who are serving today and dying today are the middle class and lower middle class," he observed.

The call to consider a imposing a draft comes just days after the Pentagon moved to extend the missions of some 20,000 of the 135,000 US troops in Iraq.

Some critics of the US-led occupation complain that military planners used too few troops to subdue Iraq, and insist that more military muscle will be needed to restore order.

The US-led military coalition was put under further strain by the announcement this week by coalition members Spain and Honduras that they would withdraw their military contingents from Iraq.

Meanwhile, witnesses at the hearing, including academics and former US officials, expressed concern about ongoing flareups of violence in Iraq this month -- the bloodiest yet for US troops.

"I think it's clear that pressures in Iraq have reached the boiling point," said Samuel Berger, national security adviser during the Bill Clinton administration, who called for an increase in troops there, and a "genuine, non-grudging effort to internationalize the enterprise in Iraq, both military and civilian."

"We've got to be prepared to give up our hammerlock on decision making in exchange for genuine burden sharing."

Richard Perle, a former White House adviser who currently serves as a fellow at a conservative think tank, advised against adding troops or extending the date of handover of Iraqi sovereignty beyond the currently-set June 30 date.

I guess we need some fresh buckhorns from Alabamer like this guy over there in the big fight!

"It is essential that we not delay the handover of sovereignty set for the end of June, even if there is continuing violence by those who know they have no place in a decent, democratic Iraq," he said.

Perle also warned against entrusting the United Nations with the post-occupation administration of Iraq, saying UN involvement should be kept at "an absolute minimum."

"A large UN contingent in Iraq ... would do more harm than good," Perle said.

"It would discourage the assumption of sovereignty by Iraqis themselves. It would drain resources urgently needed for the development of Iraq's economy," Perle said.

A senior Democrat meanwhile, lashed out at the White House for failing to send a top administration official to appear before the panel.

"I think it is outrageous that the administration has not provided every witness we've asked for," said Senator Joseph Biden, the highest-ranking Democrat on the committee.

"The fact that they are not prepared to send a witness means that they are either totally incompetent and they don't have anything to tell us ... or they're refusing to allow us to fulfill our constitutional responsibility" of congressional oversight, Biden said.

The committee's Republican chairman, Richard Lugar, also slammed the White House for "inadequate planning and communication related to Iraq."