BRUSSELS—President Donald Trump pressed allies to double their military spending target to 4% of GDP, while questioning NATO’s value and bashing Germany for supporting a gas deal with Russia.
Following his proposal, Mr. Trump and NATO’s 28 other leaders agreed to a joint summit declaration that recommitted them to moving toward the 2% target by 2024 and welcomed progress made in raising military spending.
Then, after leaving the summit, Mr. Trump called for allies to raise their military spending to 2% “IMMEDIATELY, not by 2025”—misstating the year and not mentioning his earlier proposal.
Mr. Trump’s remarks on spending and his attacks on Germany created a strained summit, dashing the hopes of diplomats and some U.S. officials for a meeting that would showcase trans-Atlantic unity ahead of the U.S. leader’s meeting with Russian President Vladimir Putin next week.
Mr. Trump, who left the NATO meeting shortly after making his 4% suggestion, capped the day by questioning on Twitter the point of the alliance, citing Germany’s support for a Russian gas project.
Bulgarian President Rumen Radev described a tense response among leaders. “Everybody asked themselves how serious Trump is about the 4%,” he said.
On Wednesday evening, at a working dinner for NATO leaders that was closed to reporters, Mr. Trump struck a more conciliatory tone, according to a European diplomat with direct knowledge of the conversations.
“It was much more consensual. He was not rocking the boat,” the diplomat said, adding that the president spent much of his time discussing his optimism about denuclearization in North Korea following his summit with leader Kim Jong Un last month.
The diplomat said Mr. Trump also spoke about how he had asked Kim whether he knew the Elton John CD containing the song “Rocket Man”—a name Mr. Trump once gave to Mr. Kim.
Mr. Trump said earlier this week that Mr. Pompeo hadn’t given the North Korean leader the CD, and that it would be “given at a different period.”
At the dinner, allies told Mr. Trump that talks with Mr. Putin could be useful, but urged the president to stress the importance of international rules-based order, the diplomat said. Mr. Trump offered no detail on his plans and expectations for the Putin meeting.
A NATO official said that expectations were low for the summit and drew parallels to the Group of Seven meeting in Canada last month, which ended with Mr. Trump attacking the host nation’s prime minister as “dishonest” and “weak.”
“The mood ahead of the G-7 was also quite bad and still it ended worse than expected,” the official said.
White House press secretary Sarah Sanders said the president made the same 4% suggestion at NATO last year. “President Trump wants to see our allies share more of the burden and at a very minimum meet their already stated obligations,” she said.
A U.S. administration official said Mr. Trump’s 4% comment caught his top policy advisers by surprise because he had never broached the idea with them. The official said getting 4% isn’t feasible.
Mr. Trump said earlier Wednesday that the U.S. “in actual numbers” was spending 4.2% of its GDP on defense. But figures released by NATO a day earlier put the U.S. spending share at 3.57%. Of NATO’s 29 members, 15 currently spend less than 1.5% of GDP on defense. Eight members expect to hit the 2% target this year and a total of 18 by 2024, NATO officials say.
Mr. Trump began his visit by accusing Germany of being “captive to Russia” because of its support for Nord Stream 2, an offshore pipeline that would bring gas directly from Russia via the Baltic Sea.
Speaking in a meeting with NATO Secretary General Jens Stoltenberg, Mr. Trump called Germany’s support for the project “very sad,” and said, “We’re supposed to be guarding against Russia, and Germany goes out and pays billions and billions of dollars a year to Russia.”
Turning to Mr. Stoltenberg, he said: “Explain that.”
Mr. Trump has himself been accused of being in thrall of Moscow, and U.S. special counsel Robert Mueller is investigating whether Mr. Trump’s associates colluded with Russia’s alleged election meddling efforts, which Mr. Trump has denied.
Later in the day, Mr. Trump tweeted: “What good is NATO if Germany is paying Russia billions of dollars for gas and energy?” Mr. Trump also criticized Germany’s military spending as “inappropriate.” Chancellor Angela Merkel responded that Germany is the second-largest provider of NATO troops, after the U.S.
And recalling her own experience living in Soviet-controlled East Germany, she said, “I am very happy today that we are united in freedom…Because of that, we can say that we can make our independent policies and make independent decisions.”
Germany is the biggest importer of natural gas from Russia in the EU, accounting for more than 20% of the purchases in 2017 by the 28-member bloc, according to the EU’s statistics agency Eurostat. Russia accounted for 37% of Germany’s annual gas purchases for the past two years, not 70% as Mr. Trump had claimed.
Mr. Trump and Ms. Merkel met later Wednesday on the sidelines of the summit. There, Mr. Trump struck a friendlier tone, describing his relationship with Ms. Merkel as “very, very good” and the bond between the two nations as “tremendous.” Ms. Merkel said the two nations are “good partners.”
The two leaders have had a tense relationship, as Mr. Trump has repeatedly attacked Germany’s military spending and immigration policies. The pair at one point went five months without speaking—a rarity for two nations that have been close allies in recent decades.
In Washington, the Democratic leaders of both chambers in Congress issued a rebuke of Mr. Trump’s comments, with Sen. Chuck Schumer of New York and Rep. Nancy Pelosi of California calling them “an embarrassment.”
Mr. Trump’s criticism of Germany’s relationship with Russia comes days before he is set to meet with Mr. Putin in Helsinki in an effort to reset U.S. relations with Moscow. He has met frequent criticism in Washington for appearing overly friendly toward Mr. Putin, including when he congratulated the Russian leader on his election victory earlier this year despite being advised by national security officials not to do so.
Many NATO allies are wary of Mr. Trump’s efforts to improve ties with Mr. Putin, whom he has often praised even during the investigation into Moscow’s efforts to interfere in the 2016 U.S. election. Several nations, including the U.K., expressed concern about Mr. Trump’s call earlier this year for Russia to rejoin the G-7, four years after it was expelled over its annexation of Crimea.
Much of the joint declaration NATO leaders issued Wednesday focuses on the alliance’s role as a defense against Russia, saying “aggressive actions” by the country had “reduced stability and security, increased unpredictability, and changed the security environment.”
After leaving the NATO summit early Thursday afternoon, Mr. Trump will continue his seven-day swing through Europe with a meet in London with U.K. Prime Minister Theresa May before traveling on to Scotland, where he owns two golf courses, and finally Helsinki.
As Mr. Trump shook hands with Mr. Stoltenberg at the outset of their meeting Wednesday morning, he quipped that the secretary-general liked him.
“He may be the only one,” Mr. Trump added. “But that’s OK with me.”
—Emre Peker, Robert Wall and Georgi Kantchev contributed to this article.