President Obama on Monday praised the North Atlantic Treaty Organization (NATO), which has come under criticism from Republican presidential front-runner Donald TrumpDonald TrumpRobert Gates says 'extreme polarization' is the greatest threat to US democracy Cassidy says he won't vote for Trump if he runs in 2024 Schiff says holding Bannon in criminal contempt 'a way of getting people's attention' MORE.
Obama called the organization “a lynchpin, a cornerstone” of U.S. and European security after a meeting with NATO Secretary-General Jens Stoltenberg at the White House.
Speaking to reporters in the Oval Office, Stoltenberg said NATO is “as important as ever” because it’s “been able to adapt to a more dangerous road.”
He declined to comment directly on Trump’s claims but pointed out that NATO troops fought the Taliban and al Qaeda alongside U.S. forces in Afghanistan.
"Afghanistan is our biggest military operation ever,” Stoltenberg said. “This shows importance of unity, because our military response is a direct response to 9/11 and we have fought alongside the U.S. for many years."
The two leaders discussed the fight against the Islamic State in Iraq and Syria (ISIS) as well as military campaigns in Afghanistan, Iraq and Ukraine, where the alliance is looking to counter Russia.
Obama ignored a shouted question about Trump’s remarks on whether NATO remains relevant.
White House press secretary Josh Earnest said later Monday that the meeting wasn't scheduled to rebuke Trump. He said it was organized at the beginning of the year, "long before Mr. Trump’s ill-advised comments on the importance" of the U.S. relationship with NATO.
Earnest said he would be "surprised" if Trump's remarks came up during the meeting.
The meeting comes two weeks after a string of deadly suicide bombings in Brussels, where NATO is headquartered, which have prompted new fears about the reach of ISIS.
Trump has criticized NATO as “obsolete,” saying it was built to combat the Soviet Union and not the terrorist threats of the 21st century.
He suggested on Saturday he would be OK if the European and North American military alliance split up.
The candidate said at a Wisconsin rally the United State's NATO partners are “not paying their fair share.”
“That means we are protecting them, giving them military protection and other things, and they’re ripping off the United States,” he said, according to The New York Times. “And you know what we do? Nothing. Either they have to pay up for past deficiencies or they have to get out.
“And if it breaks up NATO, it breaks up NATO.”
Obama has made remarks similar to some of Trump’s criticisms about America’s NATO allies. He referred to some European nations as “free riders” in a recent series of interviews with The Atlantic. Obama bluntly urged nations like the United Kingdom to boost military spending to provide for their own defense.
But the president praised NATO’s contributions to training troops in Iraq to fight ISIS forces and for helping to handle a major influx of migrants from the Middle East to Europe.
"We are grateful for the sacrifices that NATO troops have made,” Obama said.
This story was updated at 1:35 p.m.