Former President Jimmy Carter returned to the United States from Guyana on Sunday after becoming ill.
A statement released by Carter's nonprofit foundation, the Carter Center, did not offer much about the 39th president's condition. It said he "was not feeling well" and needed to return to Atlanta.
Carter, 90, was in the South American country to observe its general election, which is scheduled for Monday.
For the most part, Carter has remained in good health recently, and he has been active in traveling. Earlier this month, he visited the Middle East.
Former President George H.W. Bush, the oldest living president, has had several hospital visits in recent years. In December, Bush, also 90, spent nearly a week in a Houston-area hospital after experiencing shortness of breath.
Carter's visit to Guyana was part of an ongoing effort by the Carter Center to observe peaceful elections around the world.
"President Carter is hopeful about Guyana's election and expressed his commitment and that of the Carter Center to supporting Guyana in the days ahead, stressing the need for a peaceful process before, during and after the election," the center said.