Donald Trump says Emmanuel Macron has insulted the NATO alliance

U.S. President Donald Trump says Emmanuel Macron’s recent comments that NATO is experiencing "brain death" is very insulting to the military alliance’s other 28 members.

Trump took aim at the president of France with NATO Secretary General Jens Stoltenberg by his side at a meeting in London to mark the alliance's 70th birthday. He called Macron's comments "very nasty."

Macron said the alliance was experiencing "brain death" in an interview with the Economist published last month, suggesting that the alliance was becoming obsolete.

"Nobody needs NATO more than France," Trump said.

Trump has repeatedly criticized fellow NATO members and complained that too few nations are on track to meet the alliance goal of spending at least 2% of GDP on defense by 2024.

Trump also lashed out at France for a digital service tax that he said unfairly discriminates against U.S. tech companies, including Google, Apple, Facebook and Amazon.

Robert Lighthizer, the chief U.S. trade representative, recommended the U.S. respond with $2.4 billion in new tariffs on French cheese, wine and other products.

Trump is scheduled to meet Macron later Tuesday on the sidelines of the NATO summit.

Meanwhile, Turkish President Recep Tayyip Erdogan said he still would not agree to a NATO defense proposal for Poland and the Baltic nations until the alliance supported Ankara's concerns related to Syrian Kurdish fighters.

Erdogan said he would discuss the issue with the leaders of Poland and the Baltics during the London gathering.

A plan to defend the Baltic nations in case of a Russian attack requires all member states’ backing.

Turkey has accused NATO allies of backing Baltic countries' security concerns but dismissing threats to Turkey from the Kurdish fighters.

Turkey considers the Kurdish fighters to be terrorists and invaded parts of northeast Syria to drive them away from its border.