By Richard Cowan and David Lawder
WASHINGTON (Reuters) - President Barack Obama has asked the U.S. Congress to authorize aid for rebel groups fighting in Syria, a move that would put lawmakers on record backing his strategy to defeat Islamic State militants.
The request by the president came on the eve of a speech laying out his plan for the United States to lead a broad coalition against the militants who have taken large swaths of Iraq and Syria.
Obama requested that funds for training rebels be included in a stop-gap funding bill that would avert a U.S. government shutdown on Oct. 1, the start of a new fiscal year.
Senior Republicans, who control the U.S. House of Representatives, and Democrats, who control the Senate, both indicated willingness to consider Obama's plan.
Nonetheless, his request for Congress to authorize aid to moderate rebel groups in Syria is meeting with some questions.
The Democratic president has been under intense pressure from Congress, particularly Republicans, to launch more aggressive military attacks on the Islamic State.
House Appropriations Committee Chairman Hal Rogers of Kentucky said Obama called him late on Tuesday to ask that an authorization to arm Syrian rebels be included in the spending bill.
Speaking to reporters on Wednesday, Rogers said that Syria was a "quagmire." He also noted that the United States has had difficulty in the past with training and arming troops in Iraq and Afghanistan, only to have some turn against the United States or to have the arms fall into enemy hands. It was unclear, Rogers said, who the "moderate" Syrian rebels are.
Rogers also said the military authorization request was so important that it should be considered separately from his committee's government-funding bill, but noted time constraints.
Obama is due to outline in an address to the American people on Wednesday evening the United States' plans against the Islamic State, a radical Muslim organization, which has claimed credit for the beheading of two American journalists.
Known also as ISIL or ISIS, the Islamic State is attempting to create a state from parts of Syria and Iraq.
Obama's address, scheduled for 9 p.m. EDT (0100 GMT Thursday), is expected to include a request that Congress give its authorization for U.S. support and training for forces fighting the Islamic State. Obama also could outline possible U.S. air strikes against the group, which is being portrayed by U.S. officials as a fast-growing threat to the West.
Senate Majority Leader Harry Reid on Wednesday threw his support behind U.S. military efforts.
"I believe we need to train and equip Syrian rebels," Reid said. He stressed the importance of getting help from allies, though, adding, "Going it alone will not suffice."
"We must have the support of the international community if we are to rid the world" of the Islamic State, the Nevada Democrat said.
Reid, however, warned against steps that would involve U.S. troops on the ground to battle the Islamic State.
"I'm amazed that some members of Congress want to rush into war. Because that's what they're talking about – war," Reid said, without naming those lawmakers.
The authorization Obama is seeking would be attached to the stop-gap funding bill to keep government agencies operating until Dec. 11, giving Congress time to work on funding levels for the remainder of the fiscal year ending Sept. 30, 2015.
House Majority Leader Kevin McCarthy, a Republican, announced on the House floor that he and other leading lawmakers on Wednesday had received a classified briefing from the administration "regarding a significant piece of the president's strategy to confront the international terrorist organization."
McCarthy added, "Given the severity of the situation and the need for all members to properly evaluate the president's request, the House will postpone consideration" of the emergency spending bill pending Obama's speech and a classified briefing for all members of the House on Thursday.
"We stand ready to listen and work with the president to confront this growing threat," McCarthy said.
Members of Congress are hoping to wind up their legislative session within a week or so in order to return to their home states and campaign for re-election on Nov. 4.
It was not yet clear when the House might vote on the spending bill and the military authorization Obama wants attached to it.
However, there appeared to be strong support for limited U.S. military action against the Islamic State and House and Senate votes are possible next week.
(Additional reporting by Gabriel Debenedetti; Editing by Lisa Shumaker and Peter Henderson)