The Trump administration will move about 12,000 troops in Germany to Italy, Belgium and back to the United States, the Pentagon said Wednesday, under a plan that defense leaders said was designed to strengthen deterrence against Russia but that President Trump has insisted would punish Berlin.

Defense Secretary Mark T. Esper, unveiling the details of a long-awaited review of the U.S. military presence in Europe, said that about 5,600 of the troops would go to Italy and Belgium. About 6,400 will be based in the United States and conduct some rotational deployments back to Europe, he said.

The reduction, larger than previously expected, will reduce the number of U.S. troops stationed in Germany from 36,000 to 24,000, Esper told reporters at the Pentagon.

“As anyone can see, the repositioning of our forces in Europe constitutes a major strategic and positive shift, wholly in line with the [national defense strategy], and consistent with other adjustments the U.S. has made within NATO in previous times,” he said.

Trump, however, has repeatedly criticized Germany for falling short on contributions to the NATO alliance, characterizing a “tremendous delinquency” as the reason for repositioning U.S. forces.

While NATO nations share a target for spending 2 percent of their gross domestic product on defense, many member states do not meet that goal, including Germany. Asked about the troop reduction Wednesday, Trump reiterated earlier statements that Germany had not paid its “NATO fees.”

“The United States has been taken advantage of, on trade and on military and everything else for many years. And I’m here, and I’ve been straightening it out,” he told reporters. “But Germany owes billions and billions of dollars to NATO. And why would we keep all of our troops there?”

Trump has had a fraught relationship with German Chancellor Angela Merkel over defense spending and other matters.

“We are protecting Germany. So we are reducing the force because they’re not paying bills. It’s very simple,” he said. “If they start paying bills, I would rethink.”

According to a NATO analysis from last fall, both Italy and Belgium have lower per capita defense spending than Germany.

“Germany pays Russia billions of dollars a year for Energy, and we are supposed to protect Germany from Russia. What’s that all about?” Trump said in a Twitter message late Wednesday.

The plan has generated opposition from politicians of both parties, who fear it will weaken deterrence against Russia and heighten strains within NATO. In a recent defense bill, House lawmakers approved steps limiting the administration’s ability to execute the planned withdrawals. It is not clear whether the measure will appear in the final version of the bill.

Republican Sen. Mitt Romney (Utah) called the decision “a gift to Russia” that would harm U.S. interests. “It is a slap in the face at a friend and ally when we should instead be drawing closer in our mutual commitment to deter Russian and Chinese aggression,” he said in a statement.

Sen. Jack Reed (R.I.), the top Democrat on the Senate Armed Services Committee, described it as a “self-inflicted wound” that would do the opposite of what Esper said it would.

“This is the type of move Secretary Mattis was able to stand up to in the past, but this administration seems to be unraveling under the strain of the pandemic,” Reed said, referring to Jim Mattis, who as Trump’s first Pentagon chief sought to block presidential moves to buck traditional defense alliances.

Former vice president Joe Biden, the presumptive Democratic presidential nominee, has sharply criticized Trump for his treatment of foreign allies and vowed, if elected, to strengthen NATO. His chief foreign policy adviser, Tony Blinken, told Reuters this week that a Biden administration would review the decision.

At the Pentagon, Esper said the changes were one result of a lengthy review of the U.S. troop footprint, part of an attempt to modernize the military after two decades of insurgent wars and help compete against the advanced militaries of Russia and China.

The reorganization in Europe would give commanders greater flexibility, bringing a squadron of F-16 fighter jets to Italy and moving two headquarters to Mons, Belgium, he said, while scrapping a plan to move 2,500 Air Force personnel from a base in Britain to Germany.

Esper said that at least some of the forces returning to the United States, including 4,500 members of the 2nd Cavalry Regiment, would conduct rotational deployments to Poland, the Baltic states and the Black Sea region.

In addition to moving the headquarters of U.S. European Command to Belgium, Esper said the Pentagon may relocate the U.S. Africa Command, like EUCOM now located near the German city of Stuttgart.

The announced moves will cost an estimated “several billion dollars,” he said. Some troops will depart within weeks.

In a statement, NATO Secretary General Jen Stoltenberg said Washington had “consulted closely” with NATO nations.

“As we face a more unpredictable world, we are stronger and safer when we stand together,” he said.

Esper said the review of the U.S. military presence abroad had begun in the past year. He had recently indicated that a first draft of the military’s proposal would not be presented to him for review until September. But Trump, he acknowledged Wednesday, “accelerated” the European portion of the plan in the past month and announced he had approved a withdrawal from Germany.

That announcement came just weeks after military leaders discouraged Trump, who is eager to redeem his 2016 campaign pledge to downsize the U.S. military presence overseas before the November election, from ordering new withdrawals from Afghanistan and Syria.

The administration has threatened to withdraw troops from South Korea and Japan, which both host tens of thousands of U.S. personnel, amid stalled negotiations over U.S. demands for more compensation. The administration is also discussing future troop numbers with Iraq.

The U.S. military’s overseas presence is believed to be about 200,000, slightly more than when President Barack Obama left office.

Wednesday’s announcement brought immediate objections from Germany, where officials have argued they have significantly boosted defense spending in recent years. In 2019, German defense spending increased by 10 percent, to $49.3 billion, the biggest increase among the world’s 15 biggest military spenders, according to one analysis.

However, that still amounts to only around 1.3 percent of GDP. Germany said in 2019 that it would reach its 2 percent NATO defense spending target by 2031, missing a 2024 deadline.

German officials initially had been particularly rankled that they were not informed of the plans before they began to leak in the media, according to one U.S. official, who spoke on the condition of anonymity to discuss private conversations. “We are now at last talking to German officials about the issue,” he said in the past week.

German Defense Minister Annegret Kramp-Karrenbauer has been in touch with U.S. colleagues regarding the plans, ministry spokesman Arne Collatz-Johannsen said. “The numbers have been communicated, but of course there are further details which have to be discussed,” he said.

Peter Beyer, the German government’s transatlantic coordinator, said it was still possible the plans will fall through.

“There are many opponents in Washington, not only within the Democrats, but also with the Republicans and the Pentagon,” he told German news agency DPA on Monday.

Beyer had sharp criticism for Washington's handling of the decision, saying it was “unprecedented” that the government found out about the move from a newspaper report.

Morris reported from Berlin. Fiona Weber-Steihaus in Hamburg, Michael Birnbaum in Riga, Latvia, and Karoun Demirjian contributed to this report.