Former President Carter, on a trip promoting his new book, developed an upset stomach on a flight to Cleveland on Tuesday and was taken to a hospital, officials said.
Mr. Carter's grandson, Georgia state Sen. Jason Carter, said his 85-year-old grandfather was doing fine.
(Scroll down to watch President Carter's "60 Minutes" interview that aired earlier this month)
"He's definitely resting comfortably and expected to continue his book tour this week," Jason Carter said. "I haven't talked to him, but nobody in the family is concerned."
Jason Carter said earlier on his Facebook page that his grandfather had left the hospital, but he later told The Associated Press he had the wrong information. A spokeswoman at MetroHealth hospital in Cleveland confirmed he was still there Tuesday afternoon. CBS Radio News reports Mr. Carter will spend the night there.
White House spokesman Bill Burton said President Obama called Mr. Carter from Air Force One as he traveled from New Mexico to Wisconsin. Burton said Mr. Carter is feeling great and plans to resume his book tour on Wednesday.
Jackie Mayo, a spokeswoman for the Cleveland Hopkins Airport, told CBS News that Mr. Carter was taken off a Delta Airlines flight by rescue crews and transported to MetroHealth.
Earlier, a person who answered the phone at the Carter Center in Atlanta told CBS News the former president became airsick but was otherwise fine. Mr. Carter turns 86 years old Friday.
He was wheeled into an emergency room at MetroHealth on a stretcher and later was up and walking around, said Mary Atkins, who had taken her daughter to the hospital for medical treatment and saw Carter from a nearby room.
"He walked by the room and he was saying he was ready to go," she said. "They had Secret Service everywhere."
The Carter Center, the Democrat's Atlanta-based think tank, said Carter was expected to resume his book tour this week.
CBS News Affiliate WOIO-TV in Cleveland reports that Mr. Carter traveled there for a book signing. Hundreds of people were gathered outside of the bookstore hosting the signing in anticipation of Mr. Carter's arrival, WOIO-TV reports.
The event was later canceled, as was a Tuesday night appearance at the Regulator Bookshop in Durham, N.C., according to Mr. Carter's publisher.
"It's crazy for an 85-year-old guy to fly ... just to sign some books," said Regulator Bookshop co-owner John Valentine. "He's a brave guy. His health is most important."
Mr. Carter expected to continue the book tour later this week and was next scheduled to appear at two events in Washington, D.C., including one at the Smithsonian Institution, said Kathy Daneman, publicity manager at publisher Farrar, Straus & Giroux.
Mr. Carter has been traveling to promote his new book, "White House Diary," which was released last week.
In the book, Mr. Carter said he pursued an overly aggressive agenda as president that may have confused voters and alienated lawmakers. But he said the tipping points that cost him the 1980 election were the Iran hostage crisis and the Democratic primary challenge by U.S. Sen. Ted Kennedy.
Mr. Carter, a former peanut farmer elected to the White House in 1976, has spent his recent years pursuing peace and human rights, efforts that won him the Nobel Peace Prize in 2002.