US Congress may push back vote on Obama attack plan

Republican lawmakers may push a vote on training and equipping Syrian rebels until next week or beyond in order to debate President Barack Obama's strategy to defeat Islamic State militants in Iraq and Syria.

Several House Republicans emerged from a caucus meeting Thursday to say a possible quick vote on authorising the military to empower vetted, moderate Syrian rebels was looking less likely.

"We may end up being here an extra week," congresswoman Marsha Blackburn, who represents a district in Tennessee, told reporters. "It's important to address this and it's important to get it right."

Lawmakers are set to leave Washington as early as next Thursday and hit the campaign trail until the mid-term congressional elections on 4 November.

That leaves precious few days to work through Obama's strategy, which includes expanding US air strikes into Syria against the Islamic State (IS) extremist group.

The Pentagon has already been waging an air campaign against militant positions in Iraq.

The White House and top lawmakers agree that the president has the authority necessary to conduct such attacks in Syria.

But Obama wants cover from Congress in the form of authorisation for building up moderate rebel forces inside Syria who could help defeat IS.

Congressman Reid Ribble, who represents a Wisconsin district, expressed a willingness to authorise the president to aid the rebels, saying "I'm more toward that than being opposed to it."

But lawmakers - who were receiving classified briefings Thursday by administration officials on the IS threat - might be kept in Washington an extra week in order to extend debate.

"It's possible," Ribble said. "We're at the front end of this... and so there is a lot of information coming at us that still needs to be worked through."

Congressman Peter King, chairman of the House Homeland Security Committee’s subcommittee on counterterrorism and intelligence, warned against dithering too long.

"The longer there is uncertainty, to me the worse signal it sends overseas," King told reporters.

"It's important to at least resolve the troop vetting and training now, and then I believe after the election we should have a full debate" on use of force.

Some conservatives stressed Obama's strategy fell well short of what is needed to defeat IS.

"This isn't going to work," congresswoman Michele Bachmann and 2012 presidential candidate said of Obama's plan to build up moderate rebels, noting that previously vetted groups have spoken openly this year about cooperating with IS instead of fighting them.

"What we need to do is make a decision that we are going to war, and that we are going to defeat this enemy that seeks to defeat us," she said.