WASHINGTON - The Senate Foreign Relations Committee on Thursday narrowly approved the first formal authorization for the Obama administration's five-month-old military campaign against Islamic State militants in Iraq and Syria.

By a party-line 10-8 vote, the Democratic-led panel authorized U.S. airstrikes and other operations against the Sunni extremists and associated groups for up to three years.

The panel also barred the use of U.S. combat troops, except in specific circumstances.

The vote on a proposal by the committee chairman, Sen. Robert Menendez (D., N.J.), reflected the desire of lawmakers to begin playing a role in a war that is expected to continue for years.

Since the U.S. involvement began in August, U.S. aircraft have launched more than 1,000 strikes. President Obama has authorized sending about 3,100 military advisers to assist Iraqi security forces.

Democrats on the committee and Sen. Rand Paul (R., Ky.) have sought to set limits on U.S. involvement in the hope of preventing the campaign from expanding into another grueling Middle Eastern war.

Although lawmakers agreed on the need to convey a unified message to America's allies and adversaries alike, the deliberations underscored divisions between the parties.

At least on this issue, the Obama administration is closer in the debate to Republican lawmakers, most of whom contend that Congress shouldn't try to limit whether ground forces are deployed, where the war is fought, or which militant groups are targeted.

Setting limits on ground forces in the authorization "is not the way to go," Sen. Jeff Flake (R., Ariz.) said.

The Senate probably won't approve the legislation until next year, after Republicans take control of the chamber and review the issue.

Although Democrats were eager to put themselves on record as opposing another open-ended war, the limits they set were flexible. Some critics contended that they were too elastic, and that many military actions could be justified under the approved language.

The legislation says ground troops could be used to collect intelligence, support airstrikes, carry out planning or provide "other forms of advice and assistance to forces fighting [Islamic State] in Iraq or Syria."

The legislation also says the next administration could seek an extension of the three-year time limit.

Menendez said the goal was not to tie the hands of Obama and his successor, but to get Congress into the decision-making on the war. The goal of the authorization is to "create checks and balances on the commander in chief as is envisioned by the founders," he said.