Multiple sources in the room reached by ABC News did not deny that the president made those comments but said that they were not taken as a threat to pull out of the alliance.
“That is not what we understood or retained from the declarations of President Trump at the NATO summit. The heart of Trump’s message was positive,” a French source told ABC.
Another senior European NATO diplomat reiterated that the comments were not interpreted as an ultimatum.
"It was a very intense day. It was tough,” the diplomat told ABC. "It was extremely frank…he was very forceful.”
Trump didn’t hold back in voicing his other opinions about NATO spending. The diplomat said he complained about the new NATO headquarters, saying he didn’t like the design and suggesting that the building is unsafe because of the glass walls, confirming the Washington Post’s reporting.
A senior Czech official said some of Trump’s statements have been “concerning” but are “not that surprising.”
“We know the position. It was the same wording as last year,” the official said. “What is the problem is to spend so much money on the military. There is a challenge to make it stronger."
When asked if Trump said he would leave NATO unless the wealthiest economies hit 2 percent GDP by January or “we are going to do our own thing,” White House press secretary Sarah Sanders would not comment directly on the president’s reported statements but insisted he didn’t offer a new deadline for allies to meet the 2 percent standard.
President Trump “didn’t set a timetable, but he was very clear that other countries needed to step up and fulfill their obligations,” Sanders told ABC News.
Several leaders who participated in the meeting issued public denials on Thursday that Trump had threatened to walk out on NATO if his demands aren’t met.
"Trump said things plainly as is normal between friends and allies,” said Romanian President Klaus Iohannis. “We committed ourselves to spending a bit more."
"President Trump, never at any moment, either in public or in private, threatened to withdraw from NATO," French President Emmanuel Macron told reporters.
Asked if Trump in any way implied the U.S. could pull back from its commitment to – or participation in – NATO, Secretary General Jens Stoltenberg said the president did not.
“He didn't say that. He said he is very committed to NATO and the fact that we have made many important decisions on stepping up the fight against terrorism, new command structure, combined with more defense spending makes NATO stronger and we are more united because we had open and frank discussions,” Stoltenberg said.
Former NATO Deputy Secretary General Alexander Vershbow said on paper the summit was a success because of binding commitments to present a plan for increased defense spending and the development of the long-awaited Southern Strategy.
“All's well that ends well, it ended well but it was a tortured process,” Vershbow told ABC News.
“It erodes the trust that binds the alliance together if trust is going to pursue his PR agenda at their expense. It could be worse.”