Carter’s medical team continues to observe his progress, said Christina Karas, spokeswoman at MetroHealth Medical Center.

"President Carter is in very good spirits, appreciates all the good wishes being sent his way, and looks forward to getting back to his busy schedule," Karas said. She said she didn’t expect further updates Wednesday.

Carter’s publisher canceled scheduled events in Washington on Wednesday, including one at the Smithsonian Institution, to promote his new book, "White House Diary." The status of an event planned at a Columbia, S.C., bookstore Thursday was not immediately clear.

Book signings in a Cleveland suburb and Durham, N.C., were canceled Tuesday when the 85-year-old Carter fell ill on a flight to Cleveland.

Carter’s grandson, Georgia state Sen. Jason Carter, said Tuesday his grandfather was doing fine.

"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."

On Tuesday, Karas said Carter was fully alert and participating in all decision-making related to his care, and that the decision to admit him overnight was purely precautionary.

Carter was a passenger on a Delta Air Lines flight from Atlanta to Cleveland when he became ill. After the plane landed, he was taken off by rescue crews, said Jackie Mayo, a spokeswoman at Cleveland Hopkins International Airport.

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.

President Barack Obama called Carter from Air Force One as he traveled from New Mexico to Wisconsin, White House spokesman Bill Burton said. Carter was feeling great, Burton said.

In his new book, 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.

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.

He is the author of more than 20 books, including the 2006 "Palestine Peace Not Apartheid," about his experiences in the Middle East, and the 2005 "Our Endangered Values: America’s Moral Crisis."