WASHINGTON -- Fierce fighting over the Syrian border town of Kobani has allowed the U.S.-led coalition to take out large numbers of Islamic State of Iraq and Syria fighters that have been pouring in to try and take over the community, the top commander in the Middle East said Friday.

Gen. Lloyd Austin, head of U.S. Central Command, said that militants with ISIS, also known as the Islamic State of Iraq and the Levant, or ISIL, have clearly decided to make the capture of Kobani their main effort.

"My goal is to defeat and ultimately destroy ISIL," said Austin during a rare appearance in the Pentagon briefing room.

Austin said it's still possible that Kobani will fall, but the more insurgents are taken off the battlefield there, the fewer there will be to fight elsewhere.

Austin said he believes ISIS has decided Kobani would be its main effort, and as long as ISIS is pouring "legions of forces there into that area," the U.S-led coalition will focus on its defeat.

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State extremists have captured large sections of Iraq and Syria. The U.S. and an international coalition of nations have been pounding militant territory with airstrikes, including at least 60 locations around Kobani in recent days. Austin said the strikes have had an impact, restricting the enemy fighters' freedom of movement and communications.

In early fighting, Iraqi forces fled or joined the insurgents. But even after weeks of U.S. airstrikes, ISIS has made gains in western Iraq and has been moving closer to Baghdad.

Austin cautioned against expecting quick progress in Iraq. He said he believes the Iraqi government will successfully enlist the support of Sunni tribal leaders in Anbar province to turn the tide in that important region, where the militants have made recent gains.

And he said he sees no imminent threat to the international airport west of Baghdad, where U.S. Apache helicopters are monitoring ISIS efforts to make inroads on the capital.

"The campaign to destroy ISIL will take time and there will be occasional setbacks along the way," Austin said, "and particularly in these early stages of the campaign as we coach and mentor a force that is actively working to regenerate capability after years of neglect and poor leadership."

Austin commanded U.S. forces in Iraq in the final years of the 2003-2011 war.

As an example of fresh progress, Austin said Iraqi soldiers on Friday attacked north from Baghdad to Beiji, home to Iraq's largest oil refinery.