The head of the US European Command "received the instructions on the force reduction," said Christopher LaNeve, acting US Army chief of staff, at a congressional hearing on Friday, Xinhua reported.
"I've worked with him in close consultation on what that force unit would be, and it ... made the most sense for that brigade to not do its deployment in theater," LaNeve said, referring to the 2nd Armored Brigade Combat Team.
Some elements of the unit had already been sent overseas and its equipment was in transit, the general said.
The order to cancel the deployment came from US Secretary of Defense Pete Hegseth's office, according to the general. No formal announcement has been made.
Jeanne Shaheen, a Democrat who sits on the Senate Committee on Armed Services, said that Congress was not notified.
"As far as I know, we weren't notified about it," she told reporters.
The Pentagon announced two weeks ago that roughly 5,000 US troops would be withdrawn from Germany over the next six to 12 months.