Turkish President Recep Tayyip Erdogan postponed a video appearance on Thursday, only days after falling ill during a live TV interview.
Mr Erdogan was set to appear at an event to showcase a new nuclear plant at 1.30pm local time, now postponed until 4pm. His office confirmed the delay but gave no further details.
The President has been out of public view since bowing out of a live TV interview on Tuesday night, during which he fell ill.
The incident has reignited rumours of ill health as Mr Erdogan battles a tight election race scheduled for next month.
On Wednesday, he cancelled election rallies on the advice of his doctors.
His TV appearance on Tuesday began 90 minutes behind schedule and lasted only 10 minutes before the broadcast cut to a commercial break.
The 69-year-old looked to be waning during the interview before cutting it short mid-question.
The camera shook and the screen turned blank as the broadcast stopped.
A voice could be heard saying "oh wow" in the background, while someone repeatedly coughed.
Mr Erdogan returned about 15 minutes later and apologised, saying he had developed stomach flu while travelling for campaign rallies.
He was expected to use the nuclear power plant ceremony to bolster support among voters who back the Turkish leader’s “strongman” image and close ties with Russian President Vladimir Putin.
Rumours about Mr Erdogan's health have been circulating since he underwent two gastrointestinal operations in 2011 and 2012 and the speculation could undermine his image amid a tightly contested battle for the presidency.
The surgery went well on each occasion but left him with a slight slump in his gait that appears to have fed some of the social media rumours.
Health Minister Derya Yanik told Turkish television on Thursday that Mr Erdogan was on the mend.
"There is nothing to worry about, he is well," she said. "He will resume his intense programme tomorrow, I think."
