Defense Secretary Pete Hegseth on Thursday announced a review of U.S. military troops in Europe during a critical address to NATO defense ministers.

The review, which could last up to six months, “will examine America's force posture and basing in Europe” and will include consultations with the U.S. Congress.

“It will be ​designed to ensure that NATO is moving fast and irreversibly toward Europe leading, stepping up to take primary responsibility for the defense of Europe,” Hegseth said at the NATO headquarters in Brussels.

“It’s a ​review that some countries ‌will ⁠fail, and others will pass with flying colors.”

Hegseth framed the decision as part of the U.S.’ attempt to “make NATO what it was always supposed to be, a balanced alliance."

The Defense Secretary lambasted NATO allies who refused to allow the U.S. access to joint bases for offensive strikes and conflict-related activities during the Iran war.

He argued this “shameful” response had put America’s sons and daughters “at risk.” 

The fallout of the Iran war has splintered relations between U.S. President Donald Trump and several of his once-strong European allies, including U.K. Prime Minister Keir Starmer and German Chancellor Friedrich Merz.

Hegseth also raised issue with the financial contributions of allied nations and threatened to withhold dues if allies don’t meet their defense spending commitments.  

NATO allies who “go on about the rules-based international order and middle powers banding together, still seem to think the era of free-riding is here,” he claimed. “For too long, NATO has been a paper tiger, and a one-way street. No more.” 

Hegseth may have been referencing Canadian Prime Minister Mark Carney’s speech at Davos in January, during which he said “every day we're reminded that we live in an era of great power rivalry, that the rules-based order is fading, that the strong can do what they can, and the weak must suffer what they must.”

Following Hegseth’s address, NATO Secretary General Mark Rutte acknowledged there is a “broad agreement among allies on the need to step up” and said the U.S.’ position, on this front, was “completely acceptable."

Last month, Washington told NATO allies it would be scaling back the number of military assets it dedicates to the alliance—an attempt to remedy an "unhealthy co-dependence in the NATO Force Model on U.S. forces,” according to NATO's top commander, U.S. Air Force General Alexus Grynkewich.

The Trump Administration had earlier announced it was withdrawing 5,000 troops stationed in Germany. U.S. Republican lawmakers on the Armed Services Committee expressed concern that the move could send "the wrong signal to [Russian President] Vladimir Putin."

The delayed deployment of 4,000 U.S. troops to Poland sparked further concern across party aisles.

The Pentagon in May also said it had “reduced the total number of Brigade Combat Teams (BCTs) assigned to Europe from four to three,” returning the levels of BCTs in Europe to what they were in 2021.

Trump also said he would consider pulling American troops from Italy and Spain.

It’s unclear if the upcoming review of U.S. military forces in Europe will lead to the further withdrawal of troops.

The relationship between NATO and the U.S. has come under significant strain since Trump returned to the White House.

The President has leveled repeated criticisms at the organization and has even threatened to pull the U.S. out of the alliance—a move experts say would be troublesome for several reasons.

International leaders have urged restraint. When King Charles III delivered a speech to U.S. Congress during his state visit in April, he notably defended the importance of NATO and its promise of mutual defense.