Turkey's foreign minister says it cannot be expected to lead a ground operation against Islamic State (IS) militants in Syria on its own.
Mevlut Cavusoglu also called for the creation of a no-fly zone over its border with Syria after talks in Ankara with new Nato chief Jens Stoltenberg.
Turkey is under intense pressure to do more to help Kurdish forces fighting IS in the strategic Syrian town of Kobane.
Reports say IS has been pushed back towards the outskirts of Kobane.
Earlier monitoring group the Syrian Observatory for Human Rights, quoting "reliable sources", said IS controlled a third of the town and was advancing towards the centre from eastern districts.
At the scene: Stephanie Hegarty, BBC News, Turkey-Syria border
We're standing on a hill in Mursitpinar, Turkey, overlooking Kobane. The east of the city is shrouded in smoke.
We've heard reports that IS are setting fire to buildings to create a screen from the aeroplanes we hear almost constantly overhead. Those planes continue to strike to the west of the city.
Towers of black smoke have been burning for the past few hours on the top of Mistanour hill, which is under IS control.
Our Kurdish sources inside Kobane tell us that the YPG (Syrian Kurdish Popular Protection Units) have advanced in the east and that a group of Free Syrian Army fighters moved behind IS lines causing heavy losses.
But the big black IS flag still flies on a small hill and a building in the far east of Kobane.
But senior local official Idris Nassan told the BBC that "air strikes and special operations of YPG pushed them back and now they are not controlling any more the one third of Kobane".
"They are controlling some houses in the east and south-eastern sides of Kobane."
The observatory said 42 IS fighters died in Kobane on Wednesday, including 23 in US-led coalition air strikes. Kurdish forces lost 15 fighters, the group said.
Air strikes continued overnight and into Thursday morning. Plumes of smoke could be seen rising over the town, also known as Ayn al-Arab.
US Central Command confirmed that five strikes had been carried out south of Kobane during Wednesday and Thursday. They destroyed an IS training camp, support building and two vehicles, and also hit two IS units.
Mr Hassan welcomed the strikes as a "very good sign" but said that Kurdish forces urgently needed more weapons.
Analysis: Jonathan Marcus, BBC defence correspondent
Turkey has often spoken about establishing buffer zones inside Syria - both to protect its own borders and to provide areas where refugees could gather safely. But creating such zones would represent a significant military operation requiring the seizure of defendable terrain.
This might require an incursion into Syria of some significant depth and Turkish forces would immediately become targets for IS fighters.
Turkey has always argued that such a buffer zone must be accompanied by a no-fly zone to protect against the Syrian Air Force. Turkey's thinking was forged at a time when it saw the Assad regime as the main enemy. The US might argue that against IS - which has no air force - such an exclusion zone is irrelevant.
But this all goes to the central differences between Ankara and Washington, with the Turks insisting that the anti-IS campaign must be accompanied by stepped up measures against the Assad regime as well.
Turkey has stationed tanks along its border overlooking the town, but has made no move to intervene.
Mr Cavusoglu was holding talks with Mr Stoltenberg and US envoys on possible Turkish action against IS.
"It is not realistic to expect Turkey to conduct a ground operation on its own," he told a news conference.
"We are holding talks. Once there is a common decision, Turkey will not hold back from playing its part."
The US is leading an international coalition against IS after the group seized swathes of territory in Syria and Iraq, which both share a border with Turkey.
Turkey remains wary of getting involved, partly because it is concerned about arming the Kurdish forces who are fighting the militants. Turkey has fought a long civil war with its Kurdish minority.
Pro-Kurdish protesters demanding Turkish intervention have clashed with police in several cities over recent days, leaving at least 12 people dead.
There was further fighting in Istanbul on Wednesday night with protesters hurling petrol bombs at police, who responded with water cannon and tear gas.
However, the government did win parliamentary authorisation for possible military action last week.
The motion provides a legal framework for the Turkish military to launch incursions into Syria and Iraq against militants who threaten Turkey. It also allows for foreign troops to be stationed in Turkey as part of the same campaign.
Turkey - a Nato member - wants the creation of a border zone or safe haven enforced by a no-fly zone along the Syrian side of its border to stop militants moving across and to ease the influx of refugees into Turkey.
France supports the idea but the White House has said it is "not something that is under consideration right now".
Russia's foreign ministry said any plan for a buffer zone would require UN Security Council approval.
Mr Stoltenberg, speaking in Ankara, said the setting up of a no-fly zone or buffer zone inside Syria has not been discussed by Nato.
Pentagon spokesman Rear Adm John Kirby has warned that "air strikes alone are not going to save the town of Kobane. We know that and we've been saying that over and over again".
He said that ultimately rebel fighters in Syria and Iraqi troops would have to defeat IS militants, but it would take time.
Similar views were expressed by British Foreign Secretary Philip Hammond.