The Carter Center says Jimmy Carter developed an upset stomach on a flight to Cleveland and was taken to a hospital for observation.
Jackie Mayo, a spokeswoman at Cleveland Hopkins International Airport, says the 85-year-old former president was a passenger on a Delta flight to Cleveland late Tuesday morning and became ill. She says he was taken off a plane by rescue crews.
He was taken to MetroHealth Hospital, where the Carter Center says he is resting comfortably.
The website for Joseph-Beth Booksellers in Cleveland says Carter was scheduled to appear at 1 p.m. Tuesday to sign and talk about his new book, "White House Diary."
The center says he is expected to resume his book tour this week.