The French government has summoned the Turkish ambassador after the country’s leader Recep Tayyip Erdogan described President Emmanuel Macron as “brain dead.” Ahead of a Nato summit next week that both men will attend, tensions have mounted around Turkey’s military operation in north-east Syria, and its role within the trans-Atlantic defence alliance, which is also a member of the fight against ISIS. Mr Erdogan appeared to be echoing a recent assessment of Nato by Mr Macron who said the body was experiencing a "brain death" in an interview in which he questioned whether the alliance was committed to collective defence and asked who their enemy is today. Mr Macron also complained of a US leadership vacuum and said the alliance needs “a wake-up call.” Then on Thursday, he reiterated criticism of Turkey’s operation in northeast Syria against Kurdish fighters who were crucial in the international fight against ISIS extremists. “I respect the security interests of our Turkish ally … but one can’t say that we are allies and demand solidarity, and on the other hand, present allies with a fait accompli by a military intervention which jeopardizes the action of the coalition against ISIS,” Mr Macron said at a meeting with the Nato chief Jens Stoltenberg. The comments angered Turkey’s leadership and prompted President Erdogan to shoot back Friday: “You should get checked whether you’re brain dead.” “Kicking Turkey out of NATO or not, how is that up to you? Do you have the authority to make such a decision?” Mr Erdogan asked, characterizing Mr Macron as “inexperienced.” Turkey also criticized Mr Macron for agreeing to talks with a Syrian Kurd politician whom Ankara considers an extremist. France is not alone in criticising Turkey’s offensive in northern Syria, with many Western and Arab states calling against the move especially as it risks allowing thousands of ISIS fighters and supporters held in Kurdish-run camps and prisons across the region to escape. Mr Macron's adviser said that beyond the issue of Turkey's offensive in Syria, its refusal to back a Nato defence plan for the Baltic republics and Poland was unacceptable. "Turkey can't take the defence plans of Poland and the Baltic countries hostage," the adviser said. Turkey is refusing to back a Nato defence plan for the three Baltic states and Poland unless it secures more political support from its allies for its fight against Kurdish YPG militia in northern Syria. Ankara views the YPG as terrorists with links to militant Kurdish separatists in southeast Turkey. The French Foreign Ministry said in a statement that Ambassador Ismail Hakki Musa was summoned on Friday to explain “unacceptable statements … that have no place in Turkish-French relations and cannot substitute for the necessary dialogue between the two countries.” An official in Mr Macron’s office said that Nato allies are expecting “clear answers” from Turkey about its intentions in Syria. The Macron-Erdogan spat comes amid other problems within Nato that are expected to come to the fore at next week’s summit in London, including US President Donald Trump’s complaints that other members don’t spend enough on defence and differences over the alliance’s post-Cold War mission. The spat between France and Turkey also comes at a time when Nato faces serious questions over Turkey’s role after Ankara received the first shipments of Russian S-400 air defence systems. While the US lobbied hard against the purchase and has since threatened sanctions, Turkey has refused to back down. The US has repeatedly said that the Russian S-400 system was incompatible with Nato equipment and integrating it risked opening up weak spots in the alliance’s defences. Of particular concern was if Turkey also received the new state-of-the-art F-35 stealth jets being produced, tests with the S-400 could help Russia calibrate its equipment to spot the new fighters. The S-400 system was designed to tackle the new 5th generation stealth planes that themselves were developed to be able to avoid Russian detection. The US suspended Turkey’s role in producing the jets and has frozen all shipments of the most expensive weapon ever developed. Turkey has criticised this move, insisting that it can utilise both Nato and Russian weapons. Turkey last week reportedly tested their S-400 system using US-made F16 jets.