Paris (CNN) US President Donald Trump began his 48-hour visit to Paris on Saturday meeting with his host, French President Emmanuel Macron, a onetime friend who he chided on Twitter within minutes of landing in the French capital.

The men worked to paper over their differences during a morning meeting. But the effusive expressions of bonhomie that once colored their interactions were gone, replaced by businesslike handshakes and wooden declarations of cooperation.

Seconds after Air Force One touched down at Orly Airport outside Paris on Friday, Trump vented on social media about a proposal for more robust European military cooperation floated by his French counterpart days earlier.

"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 wrote. The message appeared before he'd even gotten off his plane. "Very insulting, but perhaps Europe should first pay its fair share of NATO, which the U.S. subsidizes greatly!"

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. Very insulting, but perhaps Europe should first pay its fair share of NATO, which the U.S. subsidizes greatly!

It was an inauspicious start to Trump's short visit to Paris, which kicked off Saturday morning with one-on-one talks with Macron.

At the start of the meeting, the pair seemed to gloss over whatever differences they may have on European military cooperation, saying they were aligned on burden sharing.

"We're getting along from the standpoint of fairness, and I want to be fair. We want to help Europe, but it has to be fair," Trump said. "Right now, the burden sharing has been largely on the United States as the President will say and he understands that. He understands the United States can only do so much."

Macron said his "proposals for European defense are consistent" with Trump's views. Later, a French presidential spokesman said Macron was able to clear up the "misunderstanding" about his views on Europe's defense policy during his meeting with Trump.

"I think this was a very good opportunity at least for the French President to clarify exactly what he meant, and at the end of today's talks they stated that they had reached agreement on this whole question of the vision of the transatlantic alliance and European security," the spokesman told journalists.

The reason for Trump's visit

JUST WATCHED Trump spars with Macron as he arrives in France Replay More Videos ... MUST WATCH Trump spars with Macron as he arrives in France 02:28

The morning meeting precedes the real reason for Trump's visit: marking the 100th anniversary of the World War I armistice, which will bring leaders from across Europe to the Arc de Triomphe on Sunday for a solemn ceremony.

Trump was also due to mark to the centenary with visits to burial grounds for some of the 117,000 American military personnel who died in the war. On Saturday, he was meant to visit the Aisne-Marne American Cemetery, near where the Battle of Belleau Wood was fought in 1918, though the 50-mile journey was canceled because of foul weather. His chief of staff John Kelly lay a wreath there instead.

He will deliver remarks from Suresnes American Cemetery on Sunday -- Veterans Day in the United States.

"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?" Trump tweeted on Saturday morning.

I am in Paris getting ready to celebrate the end of World War One. 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? — Donald J. Trump (@realDonaldTrump) November 10, 2018

Trump and Macron began their relationship as fast friends, extending invitations to each others' capitals for ceremony-filled visits. But differences on trade, climate change and the US withdrawal from the Iran nuclear deal have soured their ties.

The tweet only underscored Trump's willingness to blow up his global friendships if he believes it better serves the United States or his own agenda. He has taken similarly assertive stances against leaders in the United Kingdom and at NATO hours before sitting for talks.

On Tuesday, Macron called for a "real European army" during a tour of the former Western Front, according to AFP

"We have to protect ourselves with respect to China, Russia and even the United States of America," Macron said, according to the French press agency.

Macron also suggested that since the start of Trump's presidency, the US has been seen as a less reliable ally.

"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," he said.

Macron has been advocating a similar position for months.

Trump's Friday tweet could preview another high-level international meeting in which the US President distances himself from traditional American allies. Unlike the tense G7 summit in June, however, Russian President Vladimir Putin will be present at this weekend's commemoration.

Evolving relationship

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While both Trump and Macron appeared to be off to a warm start following Trump's inauguration, their relationship appears to have soured.

"Just bad. It was terrible," a source told CNN. "Macron thought he would be able to speak his mind, based on the relationship. But Trump can't handle being criticized like that."

And more recently, a senior diplomatic source told CNN that Trump was "ranting and venting on trade" with Macron during their bilateral meeting in September.

There was "some rapport" between the two, "but it's not what it (once) was," the source said.

His meeting with Macron at the Élysée Palace on Saturday morning is the only meeting with another world leader on his schedule, though more informal encounters are possible at the Armistice ceremony and a subsequent lunch on Sunday. Other leaders attending including Putin, German Chancellor Angela Merkel and British Prime Minister Theresa May.

US officials said the civil war in Syria and efforts to counter Iran would sit high on Trump and Macron's agenda. And trade -- one of Trump's signature issues when he visits with foreign leaders -- was also likely to arise.

During Macron's visit to Washington last spring for the first -- and still the only -- formal state visit, Macron lobbied the President to remain in the nuclear accord, including over an intimate dinner of dover sole at George Washington's Mount Vernon estate. But it wasn't enough to keep Trump from announcing within weeks that he was pulling out.

Since then, Macron has issued warnings against nationalism and protectionism, even as Trump fully embraced those sentiments during a dark and angry midterm election campaign.

Both men find themselves politically humbled. Trump's Republican Party lost control of the House of Representatives during the midterm vote, and ongoing vote counts have given an edge to additional Democratic candidates.

Macron, meanwhile, is sinking to new lows in polls, weighed down by unpopular reform efforts and an attitude that some French regard as aloof. Once viewed as the next center of European power as Merkel exits the stage, Macron now is fighting just to regain his standing at home.

One part of Macron's efforts was convening the Paris Peace Forum this week, intended to bring world leaders together in the goal of promoting peace just as the deadly events of 100 years ago are top of mind.

But Trump is skipping the forum, deliver his own address on Sunday afternoon before flying Air Force One back home.