The Wall Street Journal reported the unidentified senior defense official said Carey, commander of the 20th Air Force, was stripped of his command by Lt. Gen. James Kowalski, commander of the Air Force Global Strike Command, citing "a loss of trust and confidence."
It said that phrase is the "generic reason to strip officers of command."
The Air Force has attempted to improve oversight of its nuclear mission in recent years, the newspaper said.
In May 2013, 17 officers of the Minot, N.D., Air Force base were removed following inspection reviews indicating their skills were only marginal.
After that disclosure, Air Force Chief of Staff Mark Welsh said underperformance in the nuclear mission would not be tolerated.