The U.S.-led coalition targeting Islamic State militants ramped up airstrikes Thursday in the Syrian and Turkish border town of Kobani as the militant group reportedly sent reinforcements into intensified fighting against Kurdish forces.

The fight for the town situated near the Turkish frontier has become a major early test for the co-ordinated campaign aimed at degrading and destroying the terror group.

U.S. officials hope it could pull Turkey into the battle against the Islamic State as a means to opening up a new front, but also fear the country might stand aside and let two of its enemies, the Kurdish fighters and the Islamic State group, fight for the town.

Turkish officials have said that while they do not want Kobani to fall, they will not take on a greater role in the coalition’s strategy until it outlines a plan that also includes attacking Syrian President Bashar Assad.

Attacking Assad’s regime "is not the focus of our international coalition and not the focus of our efforts by the United States," State Department spokeswoman Jen Psaki said.

"Both sides also agreed that we will continue a dynamic and deepening bilateral consultation process across the multiple lines of effort against ISIL, including military support, countering foreign fighters, counter-finance, humanitarian assistance, and de-legitimizing ISIL's messaging and rhetoric," she said using and acronym for the Islamic State group.

Turkey has also asked for a buffer zone inside Syria to secure a border, but the White House and Pentagon have said the U.S. is not considering that option.

U.S. officials said Thursday the U.S. is largely talking to Turkey about other alternatives besides inserting ground forces into the fight: allowing U.S. and coalition aircraft to fly over Turkish territory; allowing its air base in Incirlik, some 100 miles from the Syrian border, to be used by U.S. or coalition planes or for logistics and training; and equipping moderate Syrian opposition forces fighting to topple Assad.

The fight for Kobani has brought Syria's civil war yet again to Turkey's doorstep, and for weeks the U.S. and its allies have pressed Ankara to take a more robust role in the coalition.

In addition, Kurds have held massive demonstrations across Turkey in which they accuse the government, which has deployed its tanks just across the frontier, of doing nothing to save the town.

As many as 19 people were killed around the nation in clashes with police over the government’s unwillingness to aid Kurds trapped in Kobani.

Protesters outraged that Turkey was “letting Kobani fall” burned Turkish flags and statues of Kemal Ataturk, the founder of the modern Turkish republic, when images of Kurds fleeing Kobani and pouring into Turkey sparked a global call for action against the terror group.

Responding to the criticism, Turkish Foreign Minister Mevlut Cavusoglu said it was unrealistic to expect Turkey to launch a ground war against the Islamic State group on its own.

Cavusoglu said Turkey is prepared to play a bigger part once a deal is reached with the coalition. "Turkey will not hold back from carrying out its role," he said.

The U.S. Central Command said five airstrikes south of Kobani since Wednesday had destroyed an Islamic State group support building and two vehicles, and damaged a training camp. The strikes also hit two groups of Islamic State fighters, it said in a statement.

The coalition airstrikes have even forced some Islamic State fighters out of Kobani.

"Indications are that Kurdish militia there continue to control most of the city and are holding out against ISIL," said the U.S. Central Command.

The Pentagon still has said the town may yet fall to the extremists because air power alone cannot prevent it.

Even with the numerous airstrikes, the Islamic State group has managed to capture a police station in Kobani, according to the Britain-based Syrian Observatory for Human Rights.

Islamic State militants launched their offensive on Kobani in mid-September, capturing several nearby Kurdish villages and steadily strengthening their control around the town. The fighting forced at least 200,000 residents to flee into Turkey.

More than 500 people have been killed in and around Kobani since the fighting began, according to The Observatory's chief, Rami Abdurrahman. He said the Islamic State group was rushing in reinforcements, indicating the extremists also view Kobani as a test of will.

The Associated Press and Fox News' Emily Casswell contributed to this report.