Pentagon officials said on Friday that they were pulling 5,000 troops from Germany and would redeploy them to the United States and other posts overseas.
The Defense Department is also canceling a plan developed under the Biden administration to place a missile-equipped artillery unit in Europe.
The moves will return U.S. forces in Europe to the level they were in 2022, before Russia began its war in Ukraine, the officials said, speaking on condition of anonymity to discuss the planning process. Last year, the Pentagon redeployed a brigade in Romania and did not send replacement forces.
The Pentagon’s latest pullback was sharply criticized on Saturday by senior Republicans in Congress, who cited the ongoing conflicts in Ukraine and the Middle East.
Sean Parnell, a Pentagon spokesman, said in a statement that the withdrawal would be completed over the next six to 12 months.
“This decision follows a thorough review of the department’s force posture in Europe and is in recognition of theater requirements and conditions on the ground,” he said.
The Defense Department — particularly during both of President Trump’s terms — has for several years considered decreasing the military presence in Germany. But senior defense officials privately made it clear that they wanted the move to be seen as a punishment for Germany, whose recent comments about the U.S. war in Iran have annoyed Mr. Trump.
Earlier this week, Germany’s chancellor, Friedrich Merz, said Iran had “humiliated” the United States, and he questioned how Mr. Trump planned to end the conflict.
“The Americans obviously have no strategy,” Mr. Merz said.
Mr. Trump then took to Truth Social, his social media site, to vent.
“The United States is studying and reviewing the possible reduction of Troops in Germany, with a determination to be made over the next short period of time,” he wrote on Thursday.
Later, he added: “The Chancellor of Germany should spend more time on ending the war with Russia/Ukraine (Where he has been totally ineffective!), and fixing his broken Country, especially Immigration and Energy, and less time on interfering with those that are getting rid of the Iran Nuclear threat, thereby making the World, including Germany, a safer place!”
On Friday, while announcing the decision, a senior Pentagon official said that Germany’s failure to contribute to the Iran war effort had frustrated the United States, and that the country’s rhetoric was inappropriate and unhelpful.
The announcement, and the criticism of Germany, represents a shift for Pentagon officials, who recently had praised Germany’s efforts to increase military spending and take over more of the burden of supporting Ukraine.
Top Republicans in Congress on Saturday said the decision was a mistake and rejected the criticism of Germany, an unusual instance of G.O.P. pushback against Mr. Trump.
Senator Roger Wicker of Mississippi and Representative Mike D. Rogers of Alabama said in a statement that Germany had “stepped up” when Mr. Trump called for European partners to increase their military spending, and had played a key role supporting U.S. forces in the air campaign against Iran.
“We are very concerned by the decision to withdraw a U.S. brigade from Germany,” they added in their statement, urging the administration to instead “maintain a strong deterrent in Europe by moving these 5,000 U.S. forces to the east.”
Mr. Wicker and Mr. Rogers also criticized the Trump administration for acting unilaterally, and said their committees would investigate the decision and “its implications for U.S. deterrence and trans-Atlantic security.”
Even if the Pentagon pulls 5,000 troops out of Germany, the country would still host the second-largest U.S. troop presence in the world, at more than 30,000, behind only Japan.
Defense officials say the United States depends on its bases in Germany to stage many of its operations in the Middle East, Europe and Africa.
The Iran war has made that clear. Many U.S. troops evacuated from bases in the Middle East that were targeted by Iran were moved to Germany. And many of the U.S. troops wounded in the war have been taken to Germany — to Landstuhl Regional Medical Center near Ramstein Air Base — for treatment.
The U.S. military’s Africa Command and European Command are also headquartered in Germany.
Defense officials said the reduction would not directly affect Landstuhl or other medical facilities in Germany where U.S. troops receive care.