The general in charge of the US Air Force's long-range nuclear missiles has been sacked .
The Air Force says Major General Michael Carey's removal was for "behaviour during a temporary duty assignment".
Officials said the sacking was not linked to the operation of the nuclear arsenal, which was safe.
On Wednesday the US Navy announced an admiral overseeing nuclear weapons forces had been sacked from the role. Officials say that was due to illegal gambling activities.
Michael Carey is a two-star general in the 20th Air Force and was responsible for maintaining intercontinental ballistic missiles (ICBMs) at three bases across the US - a total of 450 missiles.
In a statement, the Air Force said Lieutenant General James Kowalski, the commander of Air Force Global Strike Command, had made the decision.
"Kowalski made his decision based on information from an Inspector General investigation into Carey's behaviour during a temporary duty assignment," the statement said.
It said the allegations were not related to operational readiness or the inspection results of any 20th Air Force unit, and did not involve sexual misconduct.