The United States wants Europe to take over most of NATO's conventional defense capabilities - from intelligence to missiles - by 2027, Pentagon officials told diplomats in Washington this week, a tight deadline that some European officials have found unrealistic.
The message, recounted by five sources familiar with the discussion, including a US official, was conveyed at a meeting in Washington this week between Pentagon staff overseeing NATO policy and several European delegations.
Shifting this burden from the US to the European members of the North Atlantic Alliance would drastically change the way the United States, a founding member of the alliance after World War II, cooperates with its most important military partners.
At the meeting, Pentagon officials underlined that Washington is still not satisfied with the steps Europe has taken to strengthen its defense capabilities since the expansion of the Russian invasion of Ukraine in 2022.
US officials told their counterparts that if Europe fails to meet the 2027 deadline, the US could stop participating in some NATO defense coordination mechanisms, said the sources, who requested anonymity to discuss private conversations.
Some officials in Congress are aware of and concerned about the Pentagon's message to the Europeans, a US official said.
Conventional defense capabilities include non-nuclear assets, from troops to weapons, and officials did not explain how the US will measure Europe's progress toward taking on the bulk of the burden.
It was also unclear whether the 2027 deadline represented the Trump administration's position or just the views of some Pentagon officials. There is considerable disagreement in Washington over the military role the US should play in Europe.
Some European officials said the 2027 deadline was unrealistic, regardless of how Washington measures progress, as Europe needs more than money and political will to replace some American capabilities in the short term.
Among other challenges, NATO allies face delays in manufacturing the military equipment they are trying to buy. While U.S. officials have encouraged Europe to buy more U.S.-made equipment, some of the most prized weapons and defense systems take years to deliver if ordered today.
The US also contributes capabilities that cannot simply be purchased, such as intelligence, surveillance, and unique reconnaissance, which have proven essential to Ukraine's war effort.
Asked for comment, a NATO official speaking on behalf of the alliance said that European allies have begun to take on more responsibility for the continent's security, but did not comment on the 2027 deadline.
"Allies have recognized the need to invest more in defense and shift the burden of conventional defense" from the United States to Europe, the official said.
The Pentagon and the White House did not immediately respond to requests for comment.
European countries have broadly accepted US President Donald Trump's demand that they take more responsibility for their own security and have promised big increases in defence spending.
The European Union has set a goal of making the continent capable of defending itself by 2030, and says it must fill gaps in air defense, drones, cyberwarfare capabilities, munitions and other areas. Officials and analysts say that deadline is also too ambitious.
The Trump administration has repeatedly argued that European allies should contribute more to the NATO alliance, but it is not always clear where the president stands on NATO.
During the 2024 campaign, Trump frequently criticized European allies and said he would encourage Russian President Vladimir Putin to invade NATO countries that did not spend enough on defense.
But at the annual NATO leaders' summit in June, Trump enthusiastically praised European leaders for approving a US plan to increase the annual defense spending target for member states to 5% of GDP.
In the months since, Trump has oscillated between a tougher stance on Russia — the bloc’s main adversary — and, later, a willingness to negotiate with Moscow over the conflict in Ukraine. European officials have complained that they have been largely excluded from those negotiations.
At a meeting of NATO foreign ministers this week, US Deputy Secretary of State Christopher Landau said it was "clear" that NATO allies must take responsibility for the defense of Europe.
“Successive American administrations have said this in one form or another for almost my entire life… but our administration is serious,” Landau wrote in X.
