The Trump administration has privately informed European allies that Washington will no longer remain NATO’s primary conventional defense provider beyond 2027, three people familiar with classified conversations this week told Kyiv Post.

The development marks a dramatic shift that puts Europe on a strict countdown as war rages in Ukraine and uncertainty hangs over transatlantic security.

According to briefings delivered to European counterparts mid-week, senior Pentagon officials said the Indo-Pacific remains the administration’s top priority and that the US “cannot fight two wars at once,” making a structural transfer of NATO’s conventional defense responsibilities to Europe non-negotiable.

Ukraine at the center of the warning

Despite the strategic pivot, officials said that arms deliveries to Ukraine have continued and are expected to increase before Christmas, underscoring Washington’s intent to keep Kyiv armed even as it reshapes NATO’s internal burden-sharing.

A senior Western official familiar with the conversations described the message to Kyiv Post as: “Support for Ukraine remains, but Europe must be prepared for a NATO in which the United States is no longer the automatic first responder.”

Another European diplomat summarized the mood more bluntly: “Washington is telling Europe the era of US dominance in NATO is ending – and the timeline is fixed.”

Hard deadline – with consequences

European capitals were told there should be “no surprises” ahead: The Pentagon has already communicated its intention to reduce its contribution to NATO, but the latest briefings carried a significantly sharper ultimatum.

If Europe has not built a Europe-led NATO structure by 2027, the US is prepared to step back from key planning processes altogether – including the NATO Force Model (NFM) and the NATO Defense Planning Process (NDPP).

For now, US officials will continue participating in those processes, but only to facilitate Europe’s takeover. After 2027, one official said, Europe will have to “figure it out” without assuming US participation as a given.

A European defense advisor familiar with the readout said the tone was “firm, final, and unmistakably strategic.”

Smaller US imprint inside NATO HQ

While the Trump administration is not planning major troop posture changes in Europe in the immediate future, the Pentagon will reduce the number of high-ranking US officers in NATO’s command structure, opening those senior billets to Europeans.

One crucial role remains untouched: NATO’s Supreme Allied Commander Europe (SACEUR) stays American, preserving a central pillar of NATO’s military architecture.

Officials briefed on the matter added that there is no longer any overarching global force posture review being prepared within the Pentagon – only incremental adjustments to existing deployments.

Washington wants proof of European seriousness

Pentagon officials stressed their push to accelerate the NDPP but emphasized that they are agnostic about the method – only the end result matters.

What the administration wants now, one senior official said, is “verifiable evidence that Europe is finally scaling the capabilities it says it will deliver.”

European officials noted the irony that several of the big-ticket systems the US wants Europe to take over are the same ones Washington and US manufacturers have struggled to deliver on time.

Within the emerging framework, the US contribution to NATO’s regional defense plans will be tied solely to existing permanent and rotational forces already on European soil – not expanded commitments.

One Western official framed the strategic shift as follows: “This isn’t withdrawal. But it is the end of the old NATO paradigm.”