PARIS (Reuters) - France could increase its military presence to help a U.S.-led coalition fighting Islamic State in Syria and warned that a Turkish advance on a town controlled by Kurdish-backed militias would be “unacceptable”, a presidential source said on Friday.

French President Emmanuel Macron attends a conference on French education system at the CNAM in Paris, France, March 27, 2018. Ludovic Marin/Pool via Reuters

President Emmanuel Macron has been criticised at home for his response to a Turkish operation against the YPG militia, with opponents saying he has abandoned the Kurds.

The YPG militia makes up a large portion of the Syrian Democratic Forces (SDF), which have been at the forefront of the coalition’s strategy to defeat the hard-line militants.

After Macron’s meeting on Thursday with an SDF delegation that included the YPG, its political arm the PYD, and Christian and Arab officials, a senior Kurdish official said Macron had promised to send more troops to the area as part of the coalition’s efforts, provide humanitarian assistance and “mediate” between the Kurds and Ankara.

That drew a furious response from NATO ally Turkey, which considers the YPG to be an extension of the outlawed Kurdistan Workers Party (PKK), which has waged a decades-long insurgency against the state within Turkey.

Speaking to reporters to clarify the Kurdish comments, a French presidential source said Paris had seen a resurgence of Islamic State in northeast Syria and would continue its fight against the group with the SDF.

“France doesn’t foresee any new military operation on the ground in northern Syria outside of the international coalition,” the source said.

“(But) if the president felt that, in order to achieve our goals against Islamic State, we needed a moment to bolster our military intervention, then we should do it, but it would be within the existing framework,” the source said, without elaborating.

A senior Turkish official had said on Friday a French pledge to help stabilise a region of northern Syria controlled by Kurdish-dominated forces amounted to support for terrorism and could make France a “target of Turkey”.

Macron had said in December he expected the campaign against Islamic State in Syria to be completed in February.

Asked about comments by U.S. President Donald Trump that he might disengage from Syria “very soon”, the source said Paris had at this stage not received any official request to send reinforcements.

France, like the United States, has already extended arms and training to the YPG-led militia in the fight against Islamic State, and has dozens of special forces based in the region, which has infuriated Turkey.

Turkey stormed the northern Syrian town of Afrin last week, and has repeatedly threatened to push its operations further east to the SDF-controlled Manbij where U.S. troops are stationed.

Macron’s office on Thursday said the young leader had offered to mediate between the Turks and the SDF, which it said had distanced itself from the PKK.

“We will continue the dialogue with Turkey, it is an important and essential partner to find a solution to the Syrian civil war,” the source said, responding to a barrage of angry rhetoric on Friday from Ankara.

However, he warned that any military advance from Turkey to Manbij would be “unacceptable”.