Turkish troops could be used to help set up a secure zone in Syria, if there was an international agreement to establish such a haven for refugees fleeing Islamic State fighters, President Tayyip Erdogan said in comments published on Saturday.Turkey has so far declined to take a frontline role in the US-led coalition against Islamic State but officials said earlier this week Erdogan has been negotiating on what Turkey's role might now be."The logic that assumes Turkey would not take a position militarily is wrong," Erdogan said in an interview with the Hurriyet newspaper on his way back from New York, where he attended the United Nations General Assembly meetings.Erdogan said negotiations are underway to determine how and by which countries the air strikes and a potential ground operation would be undertaken and that Turkey is ready to take part."In the distribution of responsibilities, every country will have a certain duty. Whatever is Turkey's role, Turkey will play it," he said, adding that an air operation alone was not sufficient."You can't finish off such a terrorist organization only with air strikes. Ground forces are complementary ... You have to look at it as a whole. Obviously I'm not a soldier but the air (operations) are logistical. If there's no ground force, it would not be permanent," he said.Turkey would defend its border if necessary, Erdogan said and added that the necessary steps would be taken once a parliamentary mandate that enables Turkish troops to conduct operations outside its borders would be passed next week."No one is responsible for protecting your borders," Erdogan said. "Will other people come and protect? We are the ones who will protect our own borders," he said.Asked if Turkey might set up a secure zone for refugees in Syria on its own, Erdogan said: "That (should be done) with those in the region. By speaking to each one of them. Because we need to have a legitimacy within the international community."This is not only about Turkey but about 1.5 million people returning to their own land. To help settle these people are among the issues that are being discussed," he told the paper.Meanwhile early on Saturday air strikes, believed to have been carried out by U.S.-led forces, hit Islamic State and other Islamist groups in eastern Syria, the Britain-based Syrian Observatory for Human Rights said.Islamic State has maintained its grip on territory on three sides of a strategic Syrian Kurdish town on the border with Turkey, with sporadic clashes continuing on Saturday and heavy weapons fire heard, a Reuters witness said.Militants still held their positions around 10 kilometres west of Kobane inside Syria, the Reuters witness said, with Kurdish positions the last line of defence between the fighters and the town.Kobane sits on a road linking north and northwestern Syria and Kurdish control of the town has prevented Islamic State fighters from consolidating their gains, although their advance has caused more than 150,000 Kurds to flee to Turkey since last week.