A proposal by Turkey for a buffer zone inside Syria has met with a guarded response from the international community, despite being a key condition for Ankara to step up its support for the fight against jihadists.

President Recep Tayyip Erdogan over the last days has repeatedly called for the creation of a buffer zone to protect Turkey's security and house some of the over 1.5 million Syrian refugees who fled to the country.

The details of the plan have remained nebulous but reports suggest Turkey wants the enforcement of a zone extending several kilometres into Syria from the Turkish border, backed up by a no-fly zone.

The West is keen to engage Turkish support in the fight against Islamic State (IS) jihadists, with the key NATO member's well-trained and experienced army so far only looking on from the sidelines.

In a phone call with Erdogan earlier this week, French President Francois Hollande gave his support to the creation of the buffer zone, the French presidency said.

But since then, Western capitals have largely poured cold water on the idea while appearing careful not to offend the Turks by rejecting it out of hand.

NATO Secretary General Jens Stoltenberg said he discussed the idea of the buffer zone in talks Tuesday with Turkish Foreign Minister Mevlut Cavusoglu in Ankara.

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

Meanwhile the White House spokesman Josh Earnest insisted that the idea of a buffer zone is "not something that is under consideration right now."

This statement went back on earlier comments by US Secretary of State John Kerry who said said "the buffer zone is an idea that's out there, it's worth examining, it's worth looking at very, very closely."

British Defence Secretary Michael Fallon said in an interview with BBC Radio Thursday that this idea of a buffer zone "is something we will certainly look at", without committing further.

- Russia wants UN resolution -

Another potential problem for agreeing a buffer zone emerged Thursday when the Russian foreign ministry said any decision would have to be taken by the UN Security Council.

Foreign ministry spokesman Alexander Lukashevich said any unilateral attempts by one nation or a coalition to create a buffer zone would be "illegitimate".

Russia is a permanent, veto-wielding member of the UN Security Council as well as an ally of President Bashar al-Assad. Moscow would not respond positively to what it would likely regard as a grab of Syrian territory.

Turkey has come under increasing pressure from the West to help in the fight against jihadists seeking to capture the border town of Kobane currently held by Kurdish fighters.

The New York Times reported on Tuesday that far from seeing the buffer zone suggestion as a serious idea, some in the US administration see it as a time-wasting tactic by Turkey.

It said officials note that the US-led coalition has effectively imposed a no-fly zone over northern Syria already with its air bombing campaign.

US State Department spokeswoman Jen Psaki emphasised that "there are many challenges to implementing a buffer zone" and noted pointedly that "we have not been the country advocating for that."

However Ankara believes it is time the West listened to Turkey after it opened its borders to the refugees throughout the three-and-a-half year conflict in Syria.

"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.