President Donald Trump, French leader Emmanuel Macron spar during meeting at NATO summit in London

Dec. 3 (UPI) — U.S. President Donald Trump met with French President Emmanuel Macron Tuesday at a NATO summit in London, just hours after heavily criticizing him for dismissing the importance of the 70-year-old defensive alliance.

The two leaders met for a bilateral meeting on the sidelines of the NATO 70th anniversary summit, which began Monday, and were visibly terse while speaking to assembled press.

Trump had earlier slammed Macron for saying NATO was close to “brain death,” and said “nobody needs NATO more than France.”

When asked about repatriation of Islamic State insurgents, Trump facetiously asked Macron if he’d like France’s to return.

“Would you like some nice ISIS fighters?” he asked.

“Be serious,” Macron said moments later.

The pair also quibbled over a new French tax the Trump administration said unfairly taxes American tech companies. The tax has drawn U.S. threats of tariffs on more than $2 billion worth of French products.

“They’re not my favorite people, but that’s OK. I don’t care, they’re American companies,” Trump said. “And we want to tax American companies. It’s not for somebody else to tax them.

“So it’s either gonna work out, or we’ll work out some mutually beneficial tax.”

Macron said he’s “determined to defend the interests of our country and of Europe.”

Trump had earlier called Macron’s dismissal of NATO “nasty” and “disrespectful.”

“It is a very tough statement to make when you have such difficulty in France when you look at what is going on,” he said. “They have had a very rough year. You just can’t go around making statements like that about NATO. It is very disrespectful.

“NATO serves a great purpose.”

Earlier Tuesday, Trump met with NATO Secretary-General Jens Stoltenberg to start the summit, which pays tribute to NATO’s post-World War II founding in 1949 with 12 charter nations and its membership that’s since grown to 29 states.

Later, Trump met with Canadian Prime Minister Justin Trudeau and was set to meet with British Prime Minister Boris Johnson and Queen Elizabeth II later at a ceremonial event at Buckingham Palace.

“I will be meeting with him, yes,” he’d told reporters about Johnson, adding that he has “no thoughts” about Britain’s upcoming Dec. 12 elections.

“I don’t want to complicate it.”

Outside, demonstrators gathered to oppose Trump’s visit and Johnson’s handling of the planned exit from the European Union. The deadline for Britain’s departure is Jan. 31.