"What we have begun, we will finish," he told some 20,000 cheering Marines and family members on the sun-baked parade ground at this sprawling base. "A vise is closing, and the days of a brutal regime are coming to an end."

At least a dozen US Marines from Camp Lejeune have lost their lives in Iraq, where US-led forces have pushed their way over 200 mileskilometers) to the outskirts of the capital despite unexpected guerrilla tactics.

"No one who falls will be forgotten by this grateful nation. We honor their service to America. And we pray their families will receive God's comfort and God's grace," a somber Bush told the crowd.

The US leader, who was to meet privately here with families of the fallen, largely omitted past references to hard battles ahead, and could not resist a bit of levity at the expense of Saddam's elite troops.

"There's no finer sight -- no finer sight -- than to see 12,000 United States Marines and corpsmen," he said, pausing for effect. "Unless you happen to be a member of the Iraqi Republican Guard."

Bush, a US flag pin shining from the lapel of his gray suit, vowed that Iraqi leaders who resort to tactics like using "human shields" to blunt the invasion "will be treated like war criminals," and he suggested that even an attack with weapons of mass destruction could not stall US forces' advance.

"No scheme of this enemy, no crime of a dying regime, will divert us from our mission. We will not stop until Iraq is free," he told his camouflage-clad audience, most of whom had rolled up their sleeves to keep cool.

"The course is set. We're on the advance. Our destination is Baghdad, and we will accept nothing less than complete and final victory," said the US commander in chief, who later shared lunch with the enlisted soldiers.

Bush said US-led forces were bringing food, water and medicine to the beleaguered Iraqi populace, which he said was welcoming them as liberators, and vowed to help build a democratic regime there.

"Our fighting forces will press on until your entire country is free," he said, looking forward to "a country that is united, that's independent and that is released from years of sanctions and sorrow."

In Washington, two senior State Department officials said the United States plans to set up a new, temporary embassy in post-Saddam Iraq at a Baghdad hotel it plans to lease and renovate.

The day-long trip was Bush's third outside the Washington area since the war on Iraq was launched with a March 19 "decapitating" strike aimed at Saddam and top aides. All three have centered on speeches to military crowds.

The effect is to insulate Bush from doubting audiences and protesters -- except for those he may glimpse through the tinted windows of his armored limousine -- and let him bask in support.

"We love you, President Bush," one woman cried from the crowd on Thursday.

Some 17,500 troops from Camp Lejeune are deployed overseas, many in Iraq and Afghanistan.

The mammoth base takes its name from Major General John Lejeune, who commanded the Second Army Division in World War I.

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