Turkey on Thursday told the West it cannot be expected to lead a ground operation against jihadists in Syria alone, rebuffing growing pressure on Ankara to intervene militarily.

The Turkish parliament one week ago gave the government the green light to take military action against Islamic State (IS) jihadists in Iraq and Syria. But since then, Turkey's military has not made any move to do so.

The jihadists are fighting for the town of Kobane, just a few kilometres (miles) from the Turkish border. So far a strong Turkish military deployment on the border has merely looked on as the jihadists have battled into the town centre.

Foreign Minister Mevlut Cavusoglu said Turkey could not be expected to take action on its own and said the world needed to focus on ousting Syrian President Bashar al-Assad as well as fighting the jihadists.

"It's not realistic to expect that Turkey will lead a ground operation on its own," Cavusoglu said at a news conference with visiting NATO Secretary General Jens Stoltenberg.

Cavusoglu said that true peace can never be restored in Syria without the departure of "Assad and his regime".

He said that the current US-led air strikes against jihadists would not be enough to bring peace to Syria and a ground operation in coordination with anti-IS Syrian rebels should be considered.

"Air strikes can reverse the balance of power and stop IS, but will not be enough to clean the region of IS," Cavusoglu said.

"Therefore all other options, including a ground operation, should be considered and the Free Syrian Army should be supported," he said, referring to a moderate rebel force.

Turkish President Recep Tayyip Erdogan has said a safe zone for refugees, backed up by a no-fly zone, must be created inside Syria if Ankara is to consider military action there.

But the question of imposing a buffer zone in Syria is not being looked at by NATO members at this stage, Stoltenberg said.

"We discussed this issue today during our meeting here," Stoltenberg said.

"It has not been on the table of any NATO discussions yet and it is not an issue which is discussed in NATO," he added.

The White House had made clear late Wednesday that a buffer zone was not being discussed, after Secretary of State John Kerry indicated such an idea could be examined.

Russia on Thursday also said that the creation of any buffer zone in Syria needed to approved by the UN Security Council.

The New York Times newspaper reported Wednesday that the administration of US President Barack Obama was growing increasingly frustrated with Turkey's reluctance to intervene.

"There's growing angst about Turkey dragging its feet," it quoted a senior administration official as saying.

But Turkish leaders over the last days have expressed bitterness over expectations that it should shoulder the major burden after already opening its doors to over 1.5 million Syrian refugees from the conflict.

"Those who were silent in the face of the missiles and barrel bombs (used by the Assad regime) are now creating a global perception that Turkey should instantly solve the issue of Kobane by itself," Prime Minister Ahmet Davutoglu said late Wednesday.

Meanwhile retired US general John Allen, the US special envoy for the coalition against IS, was due in Ankara to persuade Turkey to take a stronger stance.

A foreign ministry official in Ankara told AFP that Turkey would make clear its concerns and the threats the country faces to Allen.

"We and our allies have some problems, but they can be resolved," the official said ahead of the talks.

Stoltenberg appeared to be wary of adding to the pressure on Turkey in public, saying that the IS jihadists posed "a great threat for the Iraqi people, the Syrian people and the region in general".

"It's important to stand in solidarity," he added, saying NATO welcomed the Turkish parliament's vote that gave authorisation for military action.

"NATO stands ready to support all allies in facing threats," he said.