BEIRUT (AP) -- For four months, Syrian Kurdish fighters battled the Islamic State group in the rubble-strewn streets of Kobani as U.S. aircraft pounded the extremists from the skies, a joint effort that ultimately expelled the militants from the town and marked their bloodiest defeat in Syria since the air campaign began in September.
The Kurds earned praise from the Pentagon, which said they had demonstrated the importance of having "a reliable, willing, capable partner on the ground."
And yet, two months later, Syria's Kurds remain largely on the outside looking in on the U.S.-led coalition's campaign against the Islamic State group. Unlike Syrian rebels, they are not included in a new U.S.-training program. And unlike their Kurdish brethren in Iraq, they have not been tapped to receive American weapons.
Instead, the Syrian Kurds' relationship with the U.S. remains loose and ad hoc, at the mercy of Washington's relationship with Turkey -- a NATO ally that has a long and fraught relationship with its own Kurdish minority and is deeply suspicious of Syria's Kurds.
For now, Kurdish leaders say their ties with the U.S. are limited to sporadic coordination on coalition airstrikes. The Kurds, who are led by the Kurdish Democratic Party (PYD) and its armed wing known as the YPG, welcome the help, but want more.
"The YPG for more than two years has proven it is the most effective force in Syria fighting terrorism and especially ISIS," said chief YPG spokesman Redur Khalil, using an alternative name for the Islamic State group. "But until now, the YPG has not been supplied with any weapons, contrary to other forces in Iraq, which the coalition is arming."
On the battlefields of Syria, the YPG gives the Americans "coordinates and information about the whereabouts" of Islamic State militants, he said, but the cooperation with the coalition doesn't extend beyond that. "We don't plan military operations together," he said.
Khalil said that even the air support is erratic.
He said U.S. airstrikes perfectly complemented a YPG assault last month that captured the IS-held town of Tel Hamees in Syria's Hassakeh province. But Kurdish forces defending the predominantly Kurdish town of Ras al-Ayn on the Turkish border from a large IS offensive saw no U.S. airstrikes for five days.
The coalition often shrugs off the inconsistent cooperation, Khalil said, by saying "there are military operations in Iraq, and they are busy there."
YPG fighters hunkered down on the front lines say they pay for the absence of air support in blood.
"It affects us a lot," said Hussein Kochar, a local YPG leader in Ras al-Ayn. "With the airstrikes, it would be much easier and we would suffer fewer casualties."
Syria's Kurds have performed a high-wire act of sorts in their country's civil war. They have carved out an autonomous zone in predominantly Kurdish areas since President Bashar Assad's forces largely withdrew from them in 2012, and have reached out to Christians and some Arabs to help govern them. In the battle for Kobani, they even fought alongside a small contingent of mainstream Syrian rebels against the Islamic State group -- a rare instance of cooperation that could provide a model for the future.
But the government still maintains small garrisons in Kurdish-controlled areas, leading many in the Syrian opposition to accuse the Kurds of working with Damascus -- charges the Kurds deny.
For the U.S., the YPG has proven a willing and capable partner, but not one worth damaging Washington's relationship with Turkey.
One American military officer said the U.S. is not committed to partnering with the Syrian Kurds, but also does not rule out future cooperation depending on circumstances and taking into account their human rights record and Turkish government concerns. The officer spoke on condition of anonymity because he was not authorized to brief the media.
"I think that's one of the main problems for the YPG still: Turkish-U.S. relations are more important than YPG-U.S. relations," said Wladimir van Wilgenburg, a Middle East analyst at the Jamestown Foundation.
That dynamic is unlikely to change anytime soon, if ever.
Turkey is a strategically located country of 70 million people with a lot to offer in the fight against the Islamic State group. It has clamped down on its border with Syria to stem the tide of foreign fighters, and is set to host a new program with the U.S. to train up to 4,000 mainstream Syrian rebels.
Ankara is wary of the Syrian Kurds and the YPG, which it believes is affiliated with the Kurdish PKK movement in southeast Turkey that has waged a 30-year insurgency.
But Turkish President Recep Tayyip Erdogan is now pursuing peace talks with the PKK, and there are signs of warmer relations with the Syrian Kurds.
A senior Turkish official said the atmosphere is better. He pointed to last month's operation that saw hundreds of Turkish troops smoothly travel through YPG-controlled territory in Syria to evacuate soldiers guarding an Ottoman tomb located on the Euphrates River.
Turkey's main concern now is that the Syrian Kurds make a clean break with Assad's government and unite with mainstream rebels, which doesn't seem to be happening yet, the official said on condition of anonymity because he wasn't authorized to brief the media.
Syria's Kurds are aware of the influence Turkey wields over their relationship with Washington.
Saleh Muslim, the president of the PYD, appealed to the U.S. to "listen to us with their own ears and see us through their own eyes, not through those of others" -- a clear reference to Ankara. Despite those obstacles, Muslim expressed optimism that the limited relationship could grow and develop.
"If you deal with each other, you get stronger over time," he told The Associated Press. "I think maybe in the future we can have very tight relations."
Associated Press writers Bram Janssen in Erbil, Iraq, Zeina Karam in Beirut, Desmond Butler in Istanbul and Robert Burns in Washington contributed to this report.