ANKARA (AFP) – Turkey said Thursday it had the right to close a key air base used by the US-led coalition to strike jihadists in Syria, as tensions mount between NATO allies Ankara and Washington.

Presidential spokesman Ibrahim Kalin said Ankara had the right to close Incirlik air base in Adana province, southern Turkey as part of its sovereign right.

“We always have in our hands the right to say ‘we will close it’ but as I said, the conditions will be assessed,” Kalin told 24 TV channel.

But he added that Turkish authorities were not conducting any urgent assessments to decide whether to close the base to coalition planes.

Turkey is part of the US-led coalition against the Islamic State group (IS) in Syria and lets Western war planes use Incirlik as a base for air raids.

Kalin’s comments came after Turkish ministers hit back at the United States over what they perceive as a lack of support for its own intervention in northern Syria and questioned Washington’s presence at the base.

Relations between Washington and Ankara have soured over the six-year conflict as the US sees Syrian Kurdish militias as an effective ground force against IS. Ankara views them as linked to Kurdish separatist rebels waging an insurgency in Turkey.

Turkish Foreign Minister Mevlut Cavusoglu said Wednesday that Ankara had seen no support from the US as it seeks to take the Syrian town of Al-Bab from IS in a battle that has seen fierce fighting.

“Our people ask, ‘why are you letting them (US-led coalition) be based at Incirlik?'” he said, quoted by NTV broadcaster.

The base — which houses dozens of American tactical nuclear weapons — was also a key flashpoint in the July 15 failed coup and several of its former Turkish personnel have since been detained.

Defence Minister Fikri Isik said Wednesday that Turkey was “questioning” the US presence at Incirlik.

But Washington sought to mollify Ankara, describing the base as “invaluable” for the fight against IS.

“The whole world has been made safer because of operations that have been conducted” from Incirlik, said Colonel John Dorrian, a top US military official.

Just days before President Barack Obama leaves office after eight years during which relations with Turkey have become frosty, Kalin appeared to suggest President-elect Donald Trump’s administration would prove better for Turkish-US relations.

“I have the impression that a Trump administration will take Turkey’s sensitivities on this issue (Incirlik) more into account,” Kalin said.