Reuters reported the information.The Pentagon has informed European diplomats that the United States expects NATO's European members to take control of the alliance's conventional defense operations by 2027, according to officials familiar with discussions held in Washington this week. The ultimatum marks a significant departure from decades of American military leadership in the transatlantic partnership.During meetings with European delegations, Defense Department officials indicated that recent European efforts to strengthen military capabilities following Russia's 2022 invasion of Ukraine have fallen short of expectations. Pentagon representatives warned that failure to meet the deadline could result in the United States withdrawing from certain NATO coordination mechanisms, sources said.The conventional defense capabilities in question span a wide range of non-nuclear military assets, including ground forces, weapons systems, and intelligence operations. However, Pentagon officials provided no specifics on how progress would be measured, leaving European partners uncertain about concrete benchmarks.European officials responding to the proposal expressed skepticism about the feasibility of the timeline. Even with increased political commitment and funding, they argued, certain American military capabilities—particularly advanced intelligence and reconnaissance systems critical to Ukraine's defense—cannot be quickly replicated or purchased off-the-shelf. Production delays for military equipment compound the challenge, with some sought-after U.S. defense systems requiring years for delivery even if ordered immediately.The European Union has already established its own target of achieving independent defense readiness by 2030, acknowledging substantial gaps in air defense, drone technology, cyber warfare, and ammunition production. Defense analysts consider even that more extended deadline highly ambitious.The Trump administration's position on NATO has oscillated between harsh criticism and praise. While the president previously suggested he might not defend alliance members failing to meet spending obligations, he celebrated European agreement to raise defense spending targets to 5% of GDP at June's NATO summit. At this week's gathering of NATO foreign ministers, Deputy Secretary of State Christopher Landau emphasized that unlike previous administrations, "our Administration means what it says" about European responsibility for continental defense.