Four U.S. servicemen were killed in action on Thursday in Anbar province, heartland of the unrelenting Sunni insurgency against U.S. forces and the Iraqi government and the most dangerous place in Iraq for American soldiers.

A fifth was killed and another wounded west of Baghdad on Friday when their patrol came under machinegun and mortar fire, the U.S. military said. At least 71 U.S. soldiers have died so far this month.

The deaths brought the U.S. toll in Iraq to 2,960, creeping closer to the 3,000 mark and adding more pressure on President Bush to find a strategy that will allow the eventual withdrawal of 135,000 U.S. troops.

While spending the upcoming holiday week at Camp David and his Texas ranch, Bush will hold high-level meetings on Iraq as he gets ready to unveil a fresh strategy in the new year, White House spokeswoman Dana Perino said on Friday.

Bush, who among other ideas is mulling a short-term boost in U.S. troops in Iraq, will be briefed by Gates on Saturday.

Bush has said he will announce a new strategy in January after listening to the advice of his military commanders, State Department officials, Iraqi leaders and Gates.

Gates would not say whether he will recommend a short-term troop surge. Military commanders have raised doubts about increasing troop strength, saying it will only delay a handover to Iraqis.

Gates said whatever strategy was decided, the Shi'ite-led Iraqi government must take the lead in curbing sectarian violence between minority Sunnis and majority Shi'ites that has killed thousands of Iraqis, many in the Iraqi capital.

"The situation in Baghdad is obviously difficult. Clearly success will only be achieved by a joint effort with Iraqis taking the lead," he said at the end of his two-day visit.

"They do have some concrete plans in mind, and putting flesh on those bones is exactly what General Casey and his team and the Iraqis will be doing in the days ahead," he said, referring to the U.S. commander in Iraq, General George Casey.

But critics of Prime Minister Nuri al-Maliki say he has done little to rein in the militias, which are tied to parties within his ruling Shi'ite Alliance and operate with impunity.

Maliki is weakened by infighting in his fractious government between different factions and a boycott by supporters of radical Shi'ite cleric Moqtada al Sadr. The Sadrists, key backers of Maliki, want a timetable for U.S. troop withdrawal.

The leader of an al Qaeda-backed group offered U.S. forces a safe withdrawal from Iraq within a month if they left their heavy weapons behind, according to an audio tape posted on the Internet on Friday.

The speaker, identified as Abu Omar al-Baghdadi, head of the so-called Islamic State in Iraq, which was announced in October by al Qaeda and groups affiliated to it, said Washington had two weeks to accept the offer.

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POLITICAL PILGRIMAGE

Officials in the Shi'ite Alliance said leaders would head to Najaf, home to Iraq's most powerful Shi'ite clerics, within two days to seek their help in uniting the Shi'ite factions.

The alliance was created with the blessing of Grand Ayatollah Ali al-Sistani, Iraq's most senior Shi'ite cleric.

"There will be a total review of the Alliance and the government's situation," said Haidar al-Ibadi, a member of parliament in the Alliance.

The Pentagon said this week that Sadr's Mehdi Army militia had overtaken Sunni Islamist al Qaeda as the greatest threat to Iraq's stability. Sadr's supporters say it is for self-defense only and does not launch revenge attacks against Sunni Arabs.

Revenge was on the minds of angry residents of Haditha northwest of Baghdad on Friday.

They called for the death penalty for four U.S. Marines charged on Thursday by the U.S. military with murder over the killing of 24 unarmed civilians in Haditha in November 2005.

"Those soldiers killed 24 people. They killed women and children, isn't that enough for them be executed? Just so that the family can have peace," said Khaled Salman, whose sister Asmaa was among those killed.

None of the murder charges carries a possible death sentence because the Marines are charged with unpremeditated murder, and the maximum possible sentence is life in prison.

(Additional reporting by Majid Hameed in Haditha)