The French government has summoned the Turkish ambassador to seek explanations after President Recep Tayyip Erdogan described his French counterpart Emmanuel Macron as "brain dead." Erdogan's jab at Macron comes ahead of a Nato summit next week.

The NATO gathering is expected to be attended by both Macron and Erdogan, amid increased tensions around Turkey's military operation in Syria and its role within the trans-Atlantic defense alliance. 

Erdogan's comment comes after Macron, complaining of a U.S. leadership vacuum, recently lamented the "brain death" of NATO and said the allies need "a wake-up call.”On Thursday, he reiterated criticism of Turkey's operation in northeast Syria against Kurdish fighters, who were crucial in the international fight against Islamic State extremists.

Reacting to Macron's comment on NATO, Erdogan said in a televised speech: "I am talking to France's president, Emmanuel Macron, and I will also say this at NATO.

"First of all, have your own brain death checked. These statements are suitable only to people like you who are in a state of brain death." 

Macron made the "brain death" comment during an interview with The Economist magazine earlier this month.  The 41-year-old had cast doubt on the NATO principle that an attack on a member would be deemed as an attack on the rest, an understanding that has been the bedrock of transatlantic ties since the alliance came into being in 1949.

 "What we are currently experiencing is the brain death of NATO," Macron said in the interview, before replying "I don't know," when asked if he still believed in the collective defense guarantee.

He also accused member states of failing to cooperate strategically on several key issues. "I totally stand by raising these ambiguities because I believe it was irresponsible of us to keep talking about financial and technical matters, given the stakes we currently face," he said after a meeting with Jens Stoltenberg, NATO's secretary general in Paris. 

Macron's sharp criticism of NATO comes at a time when ties between members have come under considerable strain over budget allocation, Turkish military operations in Syria and Ankara's growing proximity to Russia.

In a bid to mollify US President Donald Trump, ahead of the summit on 4 December in London, alliance chief Stoltenberg said European countries and Canada would boost defense spending by 4.6 percent in 2019. 

He stressed they would have spent a combined $130 billion between 2016 and the end of next year. Trump has voiced his frustration over NATO's budget on several occasions, accusing European allies of not paying their fair share.