Kurdish fighters' expulsion of Islamic State forces from the Syrian town of Kobani helped stop the momentum of the Islamist group but is not a significant turning point in the overall campaign, a senior State Department official said on Tuesday.
The setback for Islamic State in the war-ravaged town near the Turkish border did not mean "anyone is declaring mission accomplished" in the international campaign against the group, that has taken over parts of Syria and Iraq, the official said.
U.S. air strikes in liaison with Kurdish ground troops and Iraqi Kurd reinforcements allowed in from Turkey tipped the battle the Kurds' way, and the Islamic State's appetite for the fight had been undermined by heavy death tolls.
"About 90 percent of the town has been retaken and ISIL, whether on order or the fact that they are just breaking ranks, are withdrawing from the town," the official told reporters, employing a frequently used acronym for the al Qaeda offshoot.
"The entire notion of this organization that is on the march and the inevitable expansion and inevitable momentum has been halted at Kobani," added the official, speaking on condition of anonymity.
"The number of foreign fighters killed in Kobani is hugely significant," the official said, adding it was "in the four figures."
The militants had launched an assault on Kobani in September using heavy weapons seized in Iraq and forcing tens of thousands of people over the border into Turkey.
The official said some of Islamic State's best foreign fighters from Chechnya, Canada, Australia and Belgium made up the majority of militants fighting for the city, which became a focal point in the campaign in northern Syria.
By November they were struggling to hold the town.
Two critical actions in late September appear to have prevented Kobani from falling completely - a U.S. airdrop of arms to the Kurdish defenders and an agreement by Turkey to let Iraqi Kurdish reinforcements cross the border.
"Had we not done those two things, Kobani would've been gone, and you would've seen another massacre," the official said.
The official said the biggest advances on the battlefield came once a land corridor opened from Turkey to Kobani allowing supplies to reach Kurdish fighters, backed by U.S. air strikes.
Also addressing Kobani on Tuesday, Rear Admiral John Kirby, the Pentagon press secretary, said: "I think the air strikes helped a lot. It helped when we had ... a reliable partner on the ground in there who could help us fine-tune those strikes."
Over the past six weeks Western foreign fighters stationed at Raqqa, the movement's stronghold in Syria, had refused to fight in Kobani after many of their colleagues were killed, the State Department official said.