The Pentagon is planning to withdraw about 5,000 American forces from Germany, senior defense officials said Friday.

The officials characterized the move as a signal of President Trump's discontent with the level of assistance that European allies have offered in the U.S.-Iran war. Mr. Trump has publicly criticized German Chancellor Friedrich Merz and the leaders of other NATO member states for not getting directly involved in the U.S.'s military campaign against Iran.

The U.S. military has a massive presence in Germany dating back to the aftermath of World War II and the Cold War. More than 36,000 active duty troops were assigned to bases throughout Germany as of last December, along with nearly 1,500 reservists and 11,500 civilians, according to Defense Department figures. 

Japan is the only foreign country with a larger presence of U.S. troops. 

Germany is also home to the headquarters of U.S. European Command and Africa Command, and its Ramstein Air Base is a key hub for U.S. operations.

Some of the U.S. forces who are being moved out of Europe may return to the U.S. and then be deployed abroad, defense officials said, describing it as an effort to focus on the Pentagon's priorities in the U.S. homeland and the Indo-Pacific region. 

The withdrawals will not affect transports of injured troops to Landstuhl Regional Medical Center in Germany, the officials said. Landstuhl is the largest U.S. hospital abroad, and has taken care of U.S. forces injured by Iranian strikes.

Mr. Trump hinted earlier this week that he was considering troop reductions in Germany. He has grown increasingly frustrated with Merz in recent days, after the German chancellor said this week "the Americans clearly have no strategy" on Iran and argued the U.S. was being "humiliated" by Iranian negotiators.

The U.S. president later wrote in a pair of Truth Social posts that Merz "doesn't know what he's talking about" and was "interfering with those that are getting rid of the Iran Nuclear threat." Merz said Wednesday he is still on good terms with Mr. Trump. 

The back-and-forth exposed broader disagreements between Mr. Trump and many NATO allies, which have avoided directly joining the U.S.'s war with Iran and have grappled with higher energy prices due to disrupted fuel shipments. The president has threatened to leave NATO, disparaging the alliance as a "paper tiger" for not entering the war. A 2023 law prevents the president from withdrawing the U.S. from NATO without approval from Congress.

Mr. Trump has been critical of NATO for years, accusing alliance members of not spending enough on their militaries and being too reliant on the United States. In recent years, he has also argued that European countries should shoulder more responsibility for aiding Ukraine as it deals with a Russian invasion that surpassed the four-year mark in February.

The president floated withdrawing thousands of troops from Germany toward the end of his first term, a move that was cancelled by former President Joe Biden.

This is a breaking story; it will be updated.