French President Emmanuel Macron has accused Turkish forces of sometimes working with Islamic State-affiliated groups in their operations in northern Syria, AFP reports.

“When I look at Turkey they are fighting against those who fought with us shoulder to shoulder against ISIS (Islamic State) and sometimes they work with ISIS proxies.” Macron said during a press conference with US President Donald Trump at the NATO Summit in London.

The French leader has also said he stands by his previous words that NATO was experiencing a state of brain death. He insisted that no compromise should be made with the Islamic State, and that Ankara's actions against Kurdish militias in northern Syria,  that helped the allies fight the jihadist group, showed a lack of coordination in NATO.

“We have lost cooperation with Turkey, on security and trade and migration and European Union and France,” Macron said, adding that two clarifications must be made at the summit.

“How is it possible to be a member of the alliance, to work with — to be integrated and buy things from Russia?” he asked, referring to Ankara’s purchase of Russia’s S-400 missile system.

According to him, another thing that needs to be clarified is whether Turkey should remain a NATO member if Erdogan makes good on a threat to delay Baltic defence measures unless allies declare the Kurdish militia terrorists.