President Trump walks with French President Emmanuel Macron and his wife, Brigitte Macron, to plant a tree on the South Lawn at the White House in April. (Jabin Botsford/The Washington Post)

President Trump struck back at French President Emmanuel Macron on Friday after Macron called for a “true European army” so the continent can defend itself without relying on the United States, inflaming tensions between the two men as they prepare to meet one-on-one this weekend. 

As Air Force One touched down here for Trump’s two-day visit for the centennial commemoration of the end of World War I, Trump sent out a tweet — one of several during the six-hour transatlantic flight — taking umbrage at Macron’s comments on French radio this week. 

“President Macron of France has just suggested that Europe build its own military in order to protect itself from the U.S., China and Russia,” Trump tweeted Friday night, just before disembarking from the presidential plane. “Very insulting, but perhaps Europe should first pay its fair share of NATO, which the U.S. subsidizes greatly!”

Trump has long been irritated at countries in the NATO alliance that do not spend at least 2 percent of their gross domestic product on their militaries, claiming that the United States has had to subsidize the defense spending of other nations.

His sudden demand at the NATO summit this summer for other nations to spend billions more on defense rattled the annual meeting, as some diplomats viewed Trump’s remarks as a threat for the United States to withdraw from the alliance. 

In the interview with Europe 1 radio, Macron said he believes in the “project of a sovereign Europe” and that the continent would not be protected “if we don’t decide to have a true European army.”

“In front of Russia which is at our borders and which can be threatening, I would like to start a security dialogue with Russia, which is a country I respect and which is European,” Macron said in the interview, conducted during his tour of the main battlegrounds of World War I in northeastern France. “We have to have a Europe that can defend itself alone — and without only relying on the United States — in a more sovereign manner.”

 Macron also referred to Trump’s recent announcement that the United States would withdraw from the INF Treaty, a nuclear-arms-control pact that President Ronald Reagan struck with the former Soviet Union in 1987. 

The “main victim” of the withdrawal, Macron argued, is “Europe and its security.”

Macron also said Europe has to protect itself “with respect to China, Russia and even the United States” on cybersecurity matters and fading multilateralism.

The spat marks a contentious start to Trump’s weekend in this French capital and strikes a decidedly different tone from the message relayed by John Bolton, Trump’s national security adviser, who had traveled in advance to Paris this week. 

“In Paris today working together with our Allies to confront the toughest global security challenges we face together,” Bolton tweeted earlier Friday. 

Trump and Macron will meet for a bilateral meeting Saturday morning in Paris, and Macron will host a dinner later that evening for the visiting heads of state who are in town for the World War I commemoration. The official Armistice Day event will be Sunday. 

“I am in Paris getting ready to celebrate the end of World War One,” tweeted Trump on Saturday morning. “Is there anything better to celebrate than the end of a war, in particular that one, which was one of the bloodiest and worst of all time?”

Macron has also invited world leaders to participate in the Paris Peace Forum, another venue to discuss shared global challenges, but Trump is not expected to attend.