BRUSSELS (CBSNewYork) — President Donald Trump said the NATO of the future “must include a great focus on terrorism” but said member nations must “meet their financial obligations.”

Speaking at NATO headquarters during a dedication ceremony for a new 9/11 memorial, the president said “today is a day for both remembrance and resolve” and called for a moment of silence for the victims of the Manchester concert attack.

“We must be tough, we must be strong and we must be vigilant,” Trump said. “The NATO of the future must include a great focus on terrorism and immigration as well as threats from Russia and our NATO’s eastern and southern borders.”

The president then said NATO members must “finally contribute their fair share,” saying 23 NATO countries are not paying what they should be paying on defense.

“This is not fair to the people and taxpayers of the United states,” he said. “Over the last eight years, the United States spent more on defense than all other NATO countries combined. If all NATO members had spent just two percent of their GDP on defense last year, we would have another $119 billion for our collective defense and for the financing for additional NATO reserves.”

The new 9/11 memorial at NATO headquarters includes a steel beam from one of the World Trade Center towers. Trump thanked the 9/11 Memorial Museum in New York City for contributing the beam.

He also thanked German Chancellor Angela Merkel for donating a portion of the Berlin Wall, that was also unveiled Thursday.

“It is truly fitting that these two artifacts now reside here so close together at the new NATO headquarters,” Trump said, adding that he “never asked once what the new NATO headquarters cost.”

“I refuse to do that,” he said. “But it is beautiful.”

Earlier Thursday, Trump met with the president of the European Council Donald Tusk and the president of the European Commission President Jean-Claude Juncker.

NATO has agreed to join the Obama-era coalition to fight ISIS, but stopped short of waging direct war against the extremist group. Following his face-to-face meeting with Trump, Tusk said disagreement lingers over Russia.

“I am not 100 percent sure that we can say today, we means Mr. President and myself, that we have common position, common opinion about Russia,” Tusk said.

Trump, who once called NATO obsolete, also wants additional forces to join the roughly 8,400 U.S. troops in Afghanistan.

Following the meeting, he headed to the U.S. Ambassador to Belgium’s residence for a working lunch with French President Emmanuel Macron before heading to the U.S. embassy in Brussels, where protesters demonstrated against Trump’s visit outside.

“It is my great honor to be with the newly elected president of France, who ran an incredible campaign and had a tremendous victory,” Trump said.

The president will later attend a working dinner with world leaders and then it’s on to Air Force One, where Trump’s next stop will be Sicily for G7 meetings.