Trump also lashed out at France for a French digital service tax that he said unfairly discriminates against United States tech companies, including Google, Apple, Facebook and Amazon. Trump and Macron were once so close that their friendship was regarded as a "bromance".
Sitting next to NATO Secretary General Jens Stoltenberg at a one-on-one meeting between the two leaders Tuesday morning, Trump turned a photo op into a 50-minute impromptu news conference.
"You could make the case that they've been delinquent for 25-30 years", Trump said.
"So as soon as you have a member who feels they have a right to head off on their own, granted by the United States of America, they do it", Macron said, referring to Turkey's military offensive into Syria following the troop withdrawal.
But on Tuesday he insisted: "We have absolutely nothing to do with it and we wouldn't want to if you handed it to us on a silver platter".
In London at a bilateral meeting alongside NATO Secretary-General Jens Stoltenberg, Trump reacted to Macron telling The Economist magazine in early November that recent US troop actions in Syria are contributing to the "brain death" of the NATO military alliance.
"When you make a statement like that", he said of Macron's "brain dead" critique, "that is a very, very nasty statement to essentially 28, including them, 28 countries", the USA president told a news conference with the head of North Atlantic Treaty Organisation. He added that Turkey "could not have been nicer, could not have been more supportive".
Trump wasted little time, saying only half-jokingly that Macron's response to one journalist's question about how France was dealing with returning Islamic State fighters was "one of the greatest non-answers I have ever heard".More news: Federal Bureau of Investigation searching for terrorist from San Diego; offering $5 million reward
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Asked about the Labour leader, Trump again refused to intervene, saying: "I can work with anybody, I'm a very easy person to work with". Johnson is also set to host talks on Syria with Macron, Merkel and Erdogan later Tuesday.
"It is true you have foreign fighters coming from Europe, but this is a tiny minority of the overall problem", French.
Although not directly addressing Macron's comments, Trudeau said that "NATO has survived for seventy years because we've always had frank, real conversations".
Hours after the broadside, Macron and Trump sat side by side for a one-on-one meeting. "But I can tell you the districts where I won, and then they had an election in between mine, they had an election and other people got in, Democrats got in, those districts are leaning very big toward me".
"He just had the idea - Emmanuel had an idea: let's tax those companies", Trump said during a meeting with Stoltenberg. "We can't let that happen", he said of transatlantic disputes over everything from the aerospace sector to a European "digital tax" on USA technology giants.
As they answered questions from reporters, the chasm between Trump and Macron was most apparent as they discussed their concerns over Turkey's plan to purchase an anti-aircraft system from Russian Federation.