In a chaotic 28 hours at NATO, President Trump disparaged longtime allies, cast doubt on his commitment to the mutual-defense organization, and sent the 29-member pact into frenzied emergency session. Then, in a head-snapping pivot at the end, on Thursday he declared the alliance a "fine-tuned machine" that had acceded to his demands to speed up increases in military spending.
Mr. Trump claimed member nations had agreed to significantly boost their defense budgets and reaffirmed – after days of griping that the United States was being taken advantage of by its allies – that the US remains faithful to the accord. "The United States's commitment to NATO remains very strong," Trump told reporters at a surprise news conference following an emergency session of NATO members held to address his threats.
There were no immediate specifics on what Trump said he had achieved, and French President Emmanuel Macron quickly disputed Trump's claim that NATO allies had agreed to boost defense spending beyond their existing goal of 2 percent of gross domestic product.
Trump had spent his time in Brussels berating members of the military alliance for failing to spend enough of their money on defense, accusing Europe of freeloading off the US and raising doubts about whether he would come to members' defense if they were attacked.
Trump said he made his anger clear to allies on Wednesday.
"Yesterday I let them know that I was extremely unhappy with what was happening," Trump said, adding that, in response, European countries agreed to up their spending.
"They have substantially upped their commitment and now we're very happy and have a very, very powerful, very, very strong NATO," he said.
Painting a rosy portrait before he left Brussels, Trump added: "I can you tell you that NATO now is a really a fine-tuned machine. People are paying money that they never paid before. They're happy to do it. And the United States is being treated much more fairly."
With that, Trump moved on to Britain, where significant protests against him were expected. Although Trump administration officials point to the longstanding alliance between the US and Britain, Trump's itinerary in Britain will largely keep him out of central London, the center of the protests.
Instead, a series of events – a black-tie dinner with business leaders, a meeting with Prime Minister Theresa May, and an audience with Queen Elizabeth II – will happen outside the bustling city, where Mayor Sadiq Khan has been in a verbal battle with Trump.
Trump brushed off the protests, saying, "I think they like me a lot in the UK. I think they agree with me on immigration. I'm very strong on immigration."
At NATO, Trump did not specify which countries had committed to what, and it remained unclear whether any had changed their plans. He suggested an accelerated timeline, saying nations would be "spending at a much faster clip." That would mark a significant milestone for the alliance.
"Some are at 2 percent, others have agreed definitely to go to 2 percent, and some are going back to get the approval, and which they will get to go to 2 percent," he said.
US leaders for decades have pushed NATO allies to spend more on defense in an effort to more equitably share the collective defense burden.
NATO countries in 2014 set a goal of moving toward spending 2 percent of their gross domestic products on defense within 10 years. NATO has estimated that only 15 members, or just over half, will meet the benchmark by 2024 based on current trends.
Mr. Macron, in his own news conference, seemed to reject Trump's claim that NATO powers had agreed to increases beyond previous targets. He said the allies had confirmed their intention to meet the goal of 2 percent by 2024 and no more.
The emergency session came amid reports that Trump had threatened to leave the pact if allies didn't immediately up their spending. Officials said no explicit threat was made.
"President Trump never at any moment, either in public or in private, threatened to withdraw from NATO," Macron said.
Still, Trump confirmed the fears of NATO officials and allies as he sent the carefully orchestrated summit into chaos. On Thursday, Trump arrived late to the official meetings, missed scheduled sit-downs with two allies on the margins of the summit, and skipped part of a session on the NATO mission in Afghanistan to hold the impromptu news conference.
Trump had taken an aggressive tone during the summit, questioning the value of an alliance that has defined decades of American foreign policy, torching an ally, and proposing a massive increase in European defense spending.
Earlier Thursday, Trump called out US allies on Twitter, saying, "Presidents have been trying unsuccessfully for years to get Germany and other rich NATO Nations to pay more toward their protection from Russia."
He complained the US "pays tens of Billions of Dollars too much to subsidize Europe" and demanded that member nations reach their goal to spend 2 percent of GDP on defense, which "must ultimately go to 4%!"
Under fire for his warm embrace of Russia's Vladimir Putin, Trump on Wednesday also turned a harsh spotlight on Germany's own ties to Russia, alleging that a natural gas pipeline venture with Moscow has left Chancellor Angela Merkel's government "totally controlled" and "captive" to Russia.
He continued the attack Thursday, complaining that "Germany just started paying Russia, the country they want protection from, Billions of Dollars for their Energy needs coming out of a new pipeline from Russia."
"Not acceptable!" he railed before arriving late at NATO headquarters for morning meetings with the leaders of Azerbaijan, Romania, Ukraine, and Georgia.
During the trip, Trump questioned the necessity of the alliance that formed a bulwark against Soviet aggression, tweeting after a day of contentious meetings: "What good is NATO if Germany is paying Russia billions of dollars for gas and energy?"
Ms. Merkel, who grew up in communist East Germany, shot back that she had "experienced myself a part of Germany controlled by the Soviet Union, and I'm very happy today that we are united in freedom as the Federal Republic of Germany and can thus say that we can determine our own policies and make our own decisions and that's very good."
Trump tweeted that NATO countries "Must pay 2% of GDP IMMEDIATELY, not by 2025" and then rattled them further by privately suggesting member nations should spend 4 percent of their gross domestic product on defense – a bigger share than even the US currently pays, according to NATO statistics.
Still, Trump has been more conciliatory behind the scenes, including at a leaders' dinner Wednesday.
"I have to tell you that the atmosphere last night at dinner was very open, was very constructive, and it was very positive," Kolinda Grabar-Kitarovic, the president of Croatia, told reporters.
This story was reported by The Associated Press. AP writers Zeke Miller, Darlene Superville, and Ken Thomas in Washington contributed to this report.