A joint security crackdown by U.S. and Iraqi forces in Baghdad and the troubled Anbar Province began Feb. 14. Bush said "success will take months, not days or weeks" — in part because less than half of the U.S. troop reinforcements have arrived in the capital.

"There will be good days, and there will be bad days ahead as the security plan unfolds," the president said.

Still, he reported positive news, some delivered during a briefing on the war with his National Security Council and a later secure videoconference call with Iraqi Prime Minister Nouri al-Maliki from Baghdad.

Bush credited Iraqis with deploying 10 army brigades and nine national police brigades to the capital, and al-Maliki's Shiite-led government for allowing U.S. troops to go after Shiite militias as well as Sunni insurgents. He said the security push had already uncovered large caches of weapons and destroyed two major car bomb factories on the outskirts of Baghdad.

He also praised al-Maliki's government for making progress on a law establishing how oil revenue would be shared among the Iraqis and on a promise of $10 billion in Iraqi money spent on reconstruction.

What he didn't say was that Iraq missed the Dec. 31 target dates to enact the oil law, as well as laws establishing provincial elections and reversing measures that have excluded many Sunnis from jobs and government positions because they belonged to Saddam's Baath party. The U.S. is also pushing for constitutional amendments to remove articles that the Sunnis believe discriminate in favor of the Shiites and Kurds.

Democrats challenged Bush's strategy.

"By diverting attention from al-Qaida and stretching our troops to the breaking point, the Iraq war has made America less safe, not more," said Senate Majority Leader Harry Reid, D-Nev. "The war can only be won politically and by forcing Iraq's political factions to resolve their differences."

To this end, Democrats are pushing a war spending bill that includes a troop withdrawal deadline of Sept. 1, 2008. That timeline would speed up if Bush cannot certify that the Iraqi government is meeting its own benchmarks for providing security, allocating the oil revenues and making the constitutional amendments.

The spending bill has little chance of getting to Bush's desk, where he has promised a veto, because Democrats have a much-slimmer majority in the Senate. But the White House has worked aggressively anyway leading up to the House vote, fearing it could create momentum in the Senate and send an unwanted message globally.

"They have a responsibility to ensure that this bill provides the funds and the flexibility that our troops need to accomplish their mission," Bush said. "They have a responsibility to pass a clean bill that does not use funding for our troops as leverage to get special interest spending for their districts. And they have a responsibility to get this bill to my desk without strings and without delay."

The House proposal received a political boost Monday, when a large anti-war group said it supports the legislation and would lobby members to vote for it. MoveOn.org said it found 85 percent of its members back the bill even though it would not bring home troops immediately.

The endorsement is likely to put substantial pressure on liberal members who have threatened to oppose the bill because it would not end the war by December.