WASHINGTON >> The Republican-controlled House voted grudgingly to give the administration authority to train and arm Syrian rebels on Wednesday as President Barack Obama emphasized anew that American forces "do not and will not have a combat mission" in the struggle against Islamic State militants in either Iraq or Syria.

The 273-156 vote crossed party lines to an unusual degree in a Congress marked by near ceaseless partisanship. Top Republican and Democratic leaders backed Obama’s plan seven weeks before midterm elections, while dozens of rank-and-file lawmakers in both parties opposed it.

The provision was added to spending legislation that will ensure the federal government operates normally after the Sept. 30 end of the budget year. Final approval is expected in the Senate as early as Thursday.

Even supporters of the military plan found little to trumpet. "This is the best of a long list of bad options," said Rep. Jim Moran, D-Va.

One Republican supporter noted the measure includes strict limits on Obama’s authority. "Members on both sides of the aisle are very concerned that too much of Congress’ warmaking power has gone to the president," said Rep. Tom Cole of Oklahoma.

Obama’s remarks and similar comments Wednesday by House Democratic Leader Nancy Pelosi of California seemed designed to reassure liberal lawmakers that the new military mission would be limited.

Only a day earlier, Gen. Martin E. Dempsey, chairman of the Joint Chiefs of Staff, drew widespread attention when he told Congress he might recommend the use of U.S. ground combat forces if Obama’s current strategy fails to stop the militants.

Across the political aisle from the president and Pelosi, Speaker John Boehner, R-Ohio, and House Majority Leader Kevin McCarthy of California swung behind the plan. Yet many other Republicans expressed concerns that it would be insufficient to defeat militants who have overrun parts of Syria and Iraq and beheaded two American journalists.

In all, 85 Democrats and 71 Republicans voted to deny Obama the authority he sought. The measure passed on the strength of 159 votes from Republicans and 114 from Democrats.

GOP lawmakers took solace in the short-term nature of the legislation. It grants Obama authority only until Dec. 11, giving Congress plenty of time to return to the issue in a postelection session set to begin in mid-November.

While the military provision was given a separate vote in the House — to tack it onto the spending bill — it seemed unlikely there would be a yes-or-no vote in the Senate on Obama’s new military strategy to train rebel forces in Saudi Arabia to be used in conjunction with potential U.S. airstrikes.

Instead, the Senate is likely to vote only once on the legislation that combines approval for arming and training rebels with the no-shutdown federal spending provisions.

Officials put a $500 million price tag on Obama’s request to train and equip rebels. The cost generated virtually no discussion among lawmakers, who focused instead on the possible consequences of a new military mission not long after America ended participation in wars in Afghanistan and Iraq.

Testifying before a Senate Committee, Secretary of State John Kerry said the forces seeking to create an Islamic state " must be defeated. Period. End of story."

There was little, if any dissent on that, but debate aplenty about the best way to accomplish it.

"We simply don’t know if somewhere down the line it will turn our guns back against us," said Rep. Loretta Sanchez, D-Calif., giving voice to a fear that rebels seeking the removal of Syrian president Bashar Assad would eventually prove unreliable allies.

Republican Rep. Tom McClintock of California expressed a different concern. "Committing insufficient force in any conflict is self-defeating, and airstrikes alone cannot win a war," he said.

Dempsey’s day-old remarks had staying power.

U.S. troops "will support Iraqi forces on the ground as they fight for their own country against these terrorists," Obama told officers in Florida at U.S. Central Command, which oversees American military efforts in the Middle East. He added, "As your commander in chief, I will not commit you and the rest of our armed forces to fighting another ground war in Iraq."

Vice President Joe Biden said in Iowa that Gen. Dempsey’s "conclusion is that it is not needed now." Biden added: "We’ll determine that based on how the effort goes."

Pelosi said the House action "is not to be confused with any authorization to go further. … I will not vote for combat troops to engage in war."

In Baghdad, Iraq’s new prime minister told The Associated Press in an interview that his government wants no part of a U.S. ground combat mission. "Not only is it not necessary; we don’t want them. We won’t allow them," Prime Minister Haider al-Abadi said.

The measure also renews the charter of the Export-Import Bank, which helps finance purchases of U.S. exports. That postpones until next June a battle between tea party forces opposing the bank and business-oriented Republicans who support it.

The legislation also includes $88 million to combat the outbreak of Ebola in West Africa.

The bill passed on a vote of 319-108.

Associated Press writers Jim Kuhnhenn in Tampa, Florida; Robert Burns in Paris; Vivian Salama and Qassim Abdul-Zahra in Baghdad and Andrew Taylor, Alan Fram, and Erica Werner in Washington contributed to this story.