By Julie Hirschfeld Davis

New York Times News Service

BRUSSELS — President Donald Trump escalated his campaign of criticism against European allies Wednesday, accusing Germany of being “captive to Russia” and demanding all NATO members double their military spending targets.

On the first of two days of meetings with NATO leaders, Trump stopped short of any substantive breaks with the alliance, reaching agreement on a plan to improve military readiness and signing on to a joint statement that emphasized burden-sharing and harshly criticized Russia.

But coming just days before he is to meet President Vladimir Putin of Russia, Trump’s critical stance toward the allies focused additional attention on long-standing concerns by the United States about the willingness of Europe to shoulder its share of the financial burden for NATO. Trump again demanded the allies all meet their commitment to raise their military budgets to 2 percent of their economic output by 2024, but then further stepped up the pressure by saying they should make it 4 percent.

More broadly, his performance, leavened at times by a more reassuring tone, left his fellow leaders struggling anew to judge whether he was posturing to win a better deal for the United States, moving to weaken institutions at the heart of the post-World War II order or both.

Trump was primed for confrontation before the gathering was even called to order. At a breakfast with Jens Stoltenberg, the NATO secretary-general, Trump suggested that he had come to Brussels as a virtual pariah among allies, and was perfectly happy to be seen that way.

“I think the secretary-general likes Trump,” he said, alluding to allies’ stepping up their military spending in response to his pressure tactics. “He may be the only one, but that’s OK with me.”

Indeed, Trump spent the next several few hours practically ensuring it. He laid into Germany for not spending more on its military while becoming increasingly dependent on Russia for its energy needs. His criticism was based on Germany’s deal to import natural gas from Russia via a new pipeline.

He dismissed as paltry — “a very small step,” the president said — the increases that NATO member countries have made in their military budgets in part because of his repeated lectures on the issue, eschewing a victory lap his advisers had encouraged him to take in favor of a sharp slap at allies.

“Frankly, many countries owe us a tremendous amount of money for many years back, where they’re delinquent, as far as I’m concerned, because the United States has had to pay for them,” Trump said, mischaracterizing how the commitments for NATO military spending work. “This has gone on for many presidents, but no other president brought it up like I bring it up.

His comments came at a time when Trump’s own ties to Russia are under scrutiny and as he is also waging a spreading trade war that has ensnared allies — including NATO members like Canada and Germany — as well as foes and competitors like China. His approach has fueled concern among his critics at home and abroad that he is intent on deconstructing the postwar order and replacing it with an “America First” breed of transactional diplomacy.

At the same time, Trump’s aggressive pressure tactics have already yielded more military spending by NATO allies and a sharper focus on the issue of unbalanced burden-sharing within NATO that vexed Presidents Barack Obama and George W. Bush before him.

Unlike at the Group of 7 meeting in Quebec last month, Trump did not refuse to sign the declaration negotiated among officials of the member nations, although it was a mark of how much uncertainty he has created that his agreement to the basic statement of principles and goals was not a foregone conclusion.

The declaration said NATO countries “strongly condemn Russia’s illegal and illegitimate annexation of Crimea, which we do not and will not recognize.” Last month, Trump had suggested that he might be open to acknowledging Russia’s claim to Crimea. “We’re going to have to see,” he told reporters when asked about it aboard Air Force One on June 29.

The first day of the summit meeting also illustrated the ways in which Trump’s foreign policy approach matched up with his domestic political strategy. Attacking allies over trade and their willingness to pay their share of military costs has played well with his political base. The populist core of his coalition is fueled in part by anger over what his supporters consider unfair treatment of the United States on matters of trade, immigration and international affairs.

Across the Atlantic, Trump’s performance drew howls of criticism from Democrats and an implicit rebuke from the Republican-led Congress, which unanimously passed a resolution supporting NATO without debate.

The resolution, adopted overwhelmingly by the Senate on Tuesday night and taken up hastily by the House hours after Trump’s remarks Wednesday, said the United States “must remain committed to our NATO allies in the face of any aggression irrespective of their ability to meet the NATO benchmark of spending.”