NATO allies Turkey and the United States are narrowing their differences over plans to create a no-fly zone along the Syrian border, the Turkish foreign minister said on Wednesday.

However, his comments contrast with statements from the White House which suggest the two countries remain divided on how to respond to the Syria conflict.

"When the idea of a no-fly zone and safe zone emerged everybody had differing views, and some did not even understand what it meant," Foreign Minister Mevlut Cavusoglu was quoted by the state-run Anatolia news agency following a NATO meeting in Brussels.

"But we have allies, especially the United States, who have begun to understand its importance."

"I can say that our approach on this issue with the United States in particular is getting closer. We see the number of countries considering a no-fly zone or safe zone a must increasing," Cavusoglu added.

His comments, however, stood in stark contrast to messages from the United States indicating a no-fly zone was off the table for now.

On Monday, White House spokesman Josh Earnest said Washington was "open to discussing a range of options with the Turks" but that establishing a no-fly zone over Syria was not under consideration "at this point".

Turkey has been pushing for a buffer zone to be backed up by a no-fly zone inside Syria to provide shelter to refugees of the three-way fight between Syrian President Bashar al-Assad's regime, rebels and Islamic State (IS) jihadists.

Ties between the United States and Turkey have been strained over Ankara's reluctance to take robust action against IS militants who have siezed control of swaths of Iraq and Syria right up to the Turkish border.

Washington is pressing Ankara for the use of the Incirlik air base in southern Turkey to facilitate US jet strikes on IS militants.

Turkey, however, has refused to succumb to the pressure, and set several conditions for playing a greater role in the US-led coalition.

Those include the creation of a no-fly zone, as well as the training of moderate Syrian rebels fighting Assad.

Talks between US Vice President Joe Biden and Turkish leaders in Istanbul last month produced no breakthroughs on the issue. But Turkish authorities maintain both sides are working to move towards common ground.

"But we are engaged in a sincere and open dialogue," a Turkish official told AFP, speaking on condition of anonymity.

"Everyone understands each others' concerns. We are discussing ways to resolve our differences, but we are in full agreement on final objectives."