On the final leg of his first foreign trip, President Trump met with NATO leaders amid rising tensions over his stance on Russia, but also a renewed commitment to combat terrorism in the wake of the Manchester attacks.

Speaking in front of the entrance of the new NATO headquarters in Brussels, Trump returned to a common theme during his travels – fighting the war on terrorism.

“My travels and meetings have given me renewed hope that nations of many faiths can unite to defeat terrorism, a common threat to all of humanity,” said Trump during a ceremony unveiling a memorial to NATO’s Article 5, the mutual assistance clause of the alliance’s charter.

Trump, however, did not reaffirm America's commitment to that clause. And he did not shy away from calling on NATO members to pay their fair share.

“These grave security concerns are the same reason that I have been very, very direct with secretary and members of the alliance in saying that nation members must finally contribute their fair share and meet their financial obligations,” said the president.

He noted 23 of the 28 member nations are currently not paying “what they should be paying and what they are supposed to be paying for their defense.”

The awkward moment underscored the tensions between Trump and his European counterparts other matters.

Those disagreements were aired on Thursday morning after the president met with French President Emmanuel Macron and European Council president Donald Tusk.

Tusk frankly expressed his skepticism about reaching common ground on several areas of disagreement.

“Some issues remain open, like climate and trade. And I am not 100 percent sure that we can say today -- we mean Mr. President and myself -- that we have a common position, common opinions about Russia,” said Tusk.

German Chancellor Angela Merkel also publicly aired her disagreement with Trump’s immigration stance, saying that shared values, not “isolation and the building of walls that makes us successful.”