Bongo on Monday was still under observation at the King Faisal hospital in Riyadh where he was taken on Oct. 24. A medical and a diplomatic source both told Reuters that the president suffered a stroke.
Government spokesman Ike Ngouoni denied this and said that Bongo instead had “severe fatigue” after months of strenuous work.
The president was in Saudi Arabia to attend the Future Investment Initiative conference where he was scheduled to speak alongside other African leaders.
Bongo, whose family has ruled the central African oil producer for nearly a half century, has been president since succeeding his father Omar in 2009.
He narrowly won re-election in 2016 in a poll that the opposition claimed was marred by fraud. Mass protests broke out, during which the national parliament was gutted by fire.