WASHINGTON (Reuters) – President Donald Trump said on Monday the United States would cut the number of U.S. troops deployed in Germany to 25,000, a reduction of about 9,500, in a move likely to upset both his fellow Republicans in Congress and NATO allies.

In comments to reporters, Trump accused Germany of being “delinquent” in its payments to the North Atlantic Treaty Organization and vowed to stick with the plan unless Berlin changed course.

“So we’re protecting Germany and they’re delinquent. That doesn’t make sense. So I said, we’re going to bring down the count to 25,000 soldiers,” Trump said.

His remarks reflected the first official confirmation of the cut, which was first reported by the Wall Street Journal on June 5 and later confirmed to Reuters by a senior U.S. official who spoke on condition of anonymity.

That official said it was the result of months of work by the U.S. military leadership and had nothing to do with tensions between Trump and German Chancellor Angela Merkel, who thwarted his plan to host an in-person Group of Seven (G7) summit this month.

Emily Haber, German ambassador to the United States, told a virtual event on Monday that U.S. troops were not there to defend Germany but to defend transatlantic security, and added that Berlin was informed of the troop reduction plan.

Last week, other sources familiar with the matter said a number of U.S. officials at the White House, State Department and Pentagon were surprised by the decision and they offered explanations ranging from Trump’s pique over the G7 to the influence of Richard Grenell, the former U.S. ambassador to Germany and a Trump loyalist.