Poland warns Europe to prepare for ‘change’ in US ties, regardless of next president

"It is our job to explain to our U.S. partners that as long as we are feeling Russia's threat, we won't be able to engage fully there," he said referring to Asia, where European countries have far fewer forces deployed than the United States.

The comments from Sikorski, which were made after U.S. President Joe Biden announced he's withdrawing from the presidential race, underscore growing concern among Washington's European allies that the U.S. may significantly downgrade its investment into NATO, especially if former President Donald Trump and his isolationist running mate, JD Vance, are elected to the White House in November.

While Europe is more nervous about Trump's potential return, diplomats from several EU countries argue that the pivot toward Asia is a deeper trend in U.S. foreign policy and has been ongoing under Democrat as well as Republican presidents.

In addition to his comments to POLITICO, Sikorski's office has prepared a five-page document taking stock of the transatlantic relationship, which he presented to other EU foreign ministers during a gathering in Brussels on Monday.

The detailed paper urges EU and national leaders to rapidly adapt their behavior to the coming shift, but also to work collectively to dispel negative perceptions about the transatlantic relationship that have taken hold, most prominently on the Republican side.

The comments from Sikorski were made after U.S. President Joe Biden announced he's withdrawing from the presidential race. | Kevin Dietsch/Getty Images

Among other issues, EU leaders and officials need to address perceptions — correct or incorrect — that America is being taken advantage of by its trading partners, including the European Union. While the EU remains the United States' top global trading partner, a widening U.S. deficit in the trade of goods with Europe is feeding into this narrative.