PARIS, France - U.S. President Donald Trump dropped a diplomatic bombshell just as Air Force One was arriving in Paris late on Friday night.
He took aim at the leader of his host country, slamming the French president by labelling comments Macron had made as "very insulting."
The U.S. president is in Paris this weekend to commemorate the 100 year anniversary of the end of World War I.
He began his visit with an angry tweet attacking comments the French president had made earlier in the week in an interview on Europe Radio 1.
Responding to a question about cyber-attacks, and meddling by countries in elections, Macron had said Europe needed to protect itself from those threats, which he said could come from Russia, China, or even the U.S.
He also said Europe needed to be able to defend itself. "Faced by Russia, which is on our borders and which has shown that it can be threatening, we need to have a Europe that can better defend itself by itself, without depending solely on the United States," he said.
This is actually a position often put by Mr Trump, that countries around the world should be doing more towards their own security, rather than relying on the U.S.
President Macron also expressed concern about Mr Trumps' announcement earlier in the week that he was withdrawing from a nuclear deal struck with the Russians during the Reagan-Gorbachev era.
"When I see President Trump announcing that he's quitting a major disarmament treaty which was formed after the 1980s euro-missile crisis that hit Europe, who is the main victim? Europe and its security," Macron said.
On Friday night the U.S. president was taking offence to the comments.
"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," he tweeted.
"Very insulting, but perhaps Europe should first pay its fair share of NATO, which the U.S. subsidizes greatly," Trump added.
On Saturday morning, the U.S. president visited the Elysee Palace for a meeting with Macron. The pair posed for photographs at the entrance but both leaders were stony-faced and tense.
However later there appeared to be a thawing out.
"We are getting along from the standpoint of fairness," Mr Trump told reporters.
"He (Macron) understands the United States can only do so much."
"We have become very good friends, he added. "We have much in common."
Mr Macron too was playing down any perceived differences, saying he and his country's guest are being "consistent" in terms of the U.S. president's views on burden-sharing.