WASHINGTON – The U.S. military is likely to maintain and may even increase its force of more than 140,000 troops in Iraq through next spring, the top American commander in the region said Tuesday in one of the gloomiest assessments yet of when troops may come home.

Gen. John Abizaid, commander of the U.S. Central Command, said military leaders would consider adding troops or extending the Iraq deployments of other units if needed. Until sectarian violence spiked early this year, Bush administration officials had voiced hopes that this election year would see significant U.S. troop reductions in what has become a widely unpopular war.

“If it’s necessary to do that because the military situation on the ground requires that, we’ll do it,” Abizaid said of longer deployments. “If we have to call in more forces because it’s our military judgment that we need more forces, we’ll do it.”

His comments came as violence around Iraq killed at least 16 civilians on Tuesday and wounded dozens of others. Iraqi lawmakers angered by the relentless violence demanded that the defense and interior ministers appear before parliament to explain what they are doing to eliminate the death squads that have claimed hundreds of Iraqi lives.

The U.S. military said a U.S. soldier was killed Tuesday by a suicide car bomber in northern Iraq, another died of non-battle related injuries on Monday, and two others were killed Sunday.

Abizaid said that right now the number of U.S. troops “are prudent force levels” that are achieving the needed military effect. Still, his blunt assessment was the first time officials confirmed that higher troops levels would continue into next year.

Abizaid, Defense Secretary Donald H. Rumsfeld and Joint Chiefs of Staff Chairman Gen. Peter Pace are expected to meet with members of Congress later this week.

President Bush, in New York for U.N. General Assembly meetings on Tuesday, told Iraqi President Jalal Talabani that the U.S. will keep soldiers in Iraq as long as necessary. “I’ve told the president of Iraq that America has given her word to help you and we will keep our word. The people of Iraq must know that,” Bush said.

Late last year, military leaders had said they hoped to reduce troop levels to about 100,000 by the end of this year. But Abizaid said Tuesday that the rising sectarian violence and slow progress of the Iraqi government made that impossible.

“I think that this level probably will have to be sustained through the spring,” he said. “I think that we’ll do whatever we have to do to stabilize Iraq and Afghanistan and use the military power of the U.S. to do that.”

Members of Congress said they will listen to Abizaid’s recommendations.

The military commanders, said Sen. Saxby Chambliss, R-Ga., “know what’s necessary to adapt to the enemy’s tactics. And whether that means more troops or more troops just in Baghdad, I believe they will make the appropriate decisions necessary to help the Iraqi forces continue to stand up and ultimately defend their country on their own.”

But Senate Minority Leader Harry Reid, D-Nev., called the news disappointing. “We should have started redeploying at the end of this year,” he said.

Abizaid cautioned that the solution to much of Iraq’s violence _ both sectarian and insurgents _ is not necessarily “throwing more American units at the problem.”

Instead, he said the Iraqi government must improve the political and economic conditions in the embattled country, as part of an effort to get the “angry young men” off the streets. And he said there will be more emphasis on the U.S. military teams that are training the Iraqi army and police forces.

There are 147,000 U.S. forces in Iraq _ up more than 20,000 from the totals in June. Rumsfeld extended the one-year deployment of an Alaska-based Stryker brigade in July as part of the effort to stem the escalating violence in Baghdad. Abizaid said Tuesday that there are no plans to further extend that brigade’s deployment.

Abizaid said the latest security crackdown in Baghdad is improving conditions there, specifically in neighborhoods targeted by coalition and Iraqi forces. Military leaders should know by December, he said, whether the effort is working or if new tactics are required.

“The secular tensions, if left unchecked, could be fatal to Iraq,” he said. “And the center of the problem is Baghdad … It’s the area where we have to spend the most military effort.”

Sectarian executions have been a persistent problems in Baghdad. On Tuesday, Iraqi authorities said they found three blindfolded bodies dumped in eastern Baghdad _ all had been shot and bore signs of torture, trademarks of sectarian killings being waged between Shiite and Sunni Arabs.

Abizaid said that while the Baghdad campaign is the priority, the U.S. military has not abandoned the volatile western Anbar province.

Last week, Marine Maj. Gen. Richard C. Zilmer, commander of U.S. forces in western Iraq, said he has enough troops _ about 30,000 _ to accomplish his main mission to train Iraqi forces, but not enough to defeat the insurgency there.

His comments raised questions about whether additional forces are needed in Anbar. But Abizaid said that the more than 140,000 American troops, plus the 300,000 Iraqi troops and 23,000 troops from other coalition members, are enough to do what needs to be done, “not everywhere, all the time, equally _ but to bring Iraq to stability over time.”

Meanwhile, U.S. experts studying what to do next in Iraq said Tuesday that Baghdad’s government must make more progress toward controlling the violence and rebuilding the nation.

“The government of Iraq needs to show its own citizens soon _ and the citizens of the United States _ that it is deserving of continued support,” said Lee H. Hamilton, co-chairman of the independent, bipartisan Iraq Study Group, a 10-member panel asked by Congress to advise lawmakers and the administration. Hamilton, the former Democratic congressman from Indiana, was also co-chairman of the Sept. 11 commission that investigated the terrorist attacks.