BRUSSELS — The United States and its European allies on Thursday commemorated the 75th anniversary of D-Day, which freed the Continent from tyranny. But at the same time, the two sides are squabbling bitterly over the future and funding of European defense.
Washington has been pressing the European Union to spend more and do more for its own defense for well over a decade, with President Trump just the latest and loudest to do so.
Now that the European Union is actually responding, with a defense fund and a project for military cooperation and development, the United States is criticizing how it’s being done and complaining that the moves could harm trans-Atlantic cooperation and prevent American companies from competing for potentially lucrative contracts.
If anything, the spat is another reminder of the sour state of relations between the Trump administration and the European bloc and of the divisions on issues such as trade, climate change and Iran. The fact that a European plan to increase military spending — acceding to a demand from Mr. Trump — has degenerated into acrimony only emphasizes the split.
European diplomats say the issue recently boiled over at a private meeting in Washington. A senior American diplomat, Michael J. Murphy, a top official at the Bureau of Europe and Eurasian Affairs, lectured European Union ambassadors about the United States’ unhappiness with proposed restrictions on third-country participation in European Union defense projects.
Mr. Murphy warned that the European initiatives “could undermine trans-Atlantic security by duplicating NATO efforts and diverting valuable resources” and “make all of us less safe, Americans included.”
Some countries, he said in remarks obtained by The Times, “are pursuing an industrial policy under the veneer of a security policy,” with a priority on supporting national defense industries and trying to cut out participation and competition by nonbloc countries like Canada, Norway, the United States — and importantly, after Brexit, Britain.
European ambassadors who were there, members of the Political and Security Committee of the European Union, which deals with the bloc’s foreign and defense policy, said that the atmosphere was tense and that Mr. Murphy’s remarks did not leave time for discussion afterward. The envoys requested anonymity because they were not authorized to speak publicly about closed-doors meetings.
“It was quite a tough presentation, which took some of the colleagues by surprise,” said one European ambassador who was there. “The substance was not especially new to us, but we were surprised by the tone and toughness.”
There was a similar but less aggressive meeting at the Pentagon, the diplomats said, and there was more time there for conversation and discussion.
The confrontation is centered on two new European military spending initiatives.
For the first time, there will be a European Defense Fund, taken from the European Union budget for research and development, planned with a relatively modest start of 13 billion euros, or about $14.6 billion, over the 2021-27 budget.
There is also a program called, in Brussels-speak, “permanent structured cooperation,” or Pesco, in which 25 of the 28 member states agreed to work on cooperative military projects. Small coalitions of member states are already proposing projects to build attack helicopters and armored infantry vehicles.
But London and Washington have expressed concern that their defense contractors will be shut out of such projects, since the program specifies that third parties may only “exceptionally participate.”
The current draft regulations, Mr. Murphy said, “risk delinking the North American and European defense sectors after decades of hard work to increase our integration” and “would only help our adversaries and create a new irritant in trans-Atlantic relations.”
A number of Europeans find that language overblown and believe that, seeing as the Pentagon spends American taxpayer money on mostly American defense manufacturers, Europe should do the same.
Increased military spending is a hot-button topic in Europe, especially with a widely disliked Mr. Trump pushing the issue, and European politicians need to show that such spending will produce jobs at home.
“The Trump administration can’t have its cake and eat it, too,” said Stefano Stefanini, an Italian former ambassador to NATO and now a consultant in Brussels with Project Associates, a consulting firm.
“If the U.S. rightly wants the Europeans to spend more for defense, the end must be more European capability to contribute to common security,’’ he added. ‘‘To do so, Europe needs to strengthen its industrial base, and one tool to do it are the initiatives undertaken by the E.U.”
A senior State Department official, explaining the context for Mr. Murphy’s remarks, said that discussions and maneuvering were continuing. But the official, who requested anonymity to speak publicly about private talks, also complained that the Europeans had leaked to the news media a May 16 letter to Washington even before the Americans had received it.
That letter was in response to a May 1 letter from two senior Defense and State Department officials raising concerns about third-party participation that was sent to the European foreign policy chief, Federica Mogherini.
Officials in Washington also warn of a possible backlash in Congress if lawmakers deem that the European regulations are unfair.
Gordon Sondland, the American ambassador to the European Union, said that deeper integration of military supply chains “is in the interests of both the U.S. and Europe, because it produces the best results for trans-Atlantic security.’’
‘‘For this reason,’’ he added, ‘‘we want to avoid a situation where Congress or the administration could see a need to respond to anything that looks unilateral or protectionist.”
For its part, the European Union is divided. Countries such as Poland and the Baltic States — Estonia, Latvia and Lithuania — are more worried about Russia and want to stay close to Washington. Other countries, such as the Netherlands and Sweden, are also sympathetic to American concerns and want to avoid a confrontation.
But larger countries with significant defense industries or ambitions for European strategic autonomy, like France, Italy and Spain, are taking a tougher line.
France and Spain have been particularly firm in trying to restrict third-country participation, with strict regulations to ban the transfer of intellectual property developed in European defense projects, including to American companies that have European subsidiaries.
But all the European nations say that Pesco is intended to coordinate with NATO and to work on projects that fill alliance shortfalls or gaps, and they deny that the intention is to delink the European Union from the pact.
With 22 of the bloc’s 28 members in NATO, European diplomats say, there is no reason for Washington to fear that an enhanced European defense sector would be allowed to damage the trans-Atlantic alliance, its military capabilities or its integration.
In a study by Globsec, a security think tank, the authors, including Mr. Stefanini, concluded that Europeans should spend the 2 percent of gross domestic product on defense — as agreed by NATO — and move on.
“Europeans need to spend more and better on defense and security,” the report says. “It will only be sustainable if the European defense industry is a beneficiary and if the E.U. industrial base is consolidated and strengthened.”
American officials point to existing military cooperation, like on the F-35 fighter jet, a helicopter with the Italian firm Leonardo and the Marines’ use of Swedish-made rifles. Both sides argue about how much money each gives and gets.
The Europeans maintain that the American military-industrial complex is so dominant, and the sums in the European defense fund so modest, that Washington should relax.
Ms. Mogherini said, “At the moment, the E.U. is actually more open than the U.S. procurement market is for European Union companies and equipment.”
Ursula von der Leyen, the German defense minister, said that the Europeans “are doing what our American friends have been demanding we do for years.”
The regulations on third-party participation in the fund are essentially done, the Europeans say, though the Americans intend to keep pressing for changes. The regulations for Pesco are still being debated, with a decision probably slipping to July.
“It’s not finished, and it’s up to us to raise these concerns,” the senior State Department official said. “We do support European defense initiatives, the idea that we don’t is simply untrue. But we have real concerns that it shouldn’t duplicate NATO and should be open to third-party states and not harm the way our military industries already work together.”