French President Emmanuel Macron,right,said the US under President Donald Trump appeared to be "turning its back on us".Credit:AP
Trump surprised his NATO partners with last month's troop withdrawal. NATO plays no role in Syria,apart from helping the coalition fight the Islamic State extremist group. But the move was seen by Turkey,another NATO ally,as a green light to invade the region.
Trump also wrong-footed the allies by announcing a troop draw-down in Afghanistan and then declaring that peace talks with the Taliban were cancelled after a bomb attack killed a US soldier. NATO has played a major security role in the country since 2003,but its future there is now unclear.
Beyond that,the US leader publicly berated other leaders at a May 2017 summit for failing to boost their military budgets. Trump's preoccupation with defence spending has been a constant theme since he came to office in 2016 and is expected to feature at the next NATO summit,in London on December 3 and 4.
Macron said European members of the 29-nation alliance"should reassess the reality of what NATO is in the light of the commitment of the United States."
More broadly,Trump's trade tariffs against the EU also have rankled European members of NATO. And his decision to pull the US out of the Paris climate agreement particularly annoyed Macron.