A White House official told reporters that President Trump is "exhausted" just three days into his first trip abroad as president.
Trump was expected to say "Islamist extremism" during his speech to Muslim leaders in Saudi Arabia, but instead said "Islamic extremism."
When asked why Trump deviated from the prepared text of his speech, an administration official said Trump is "just an exhausted guy."
After the speech, Trump reportedly canceled his appearance at the Tweeps Forum. Ivanka Trump filled in for her father, speaking to about 400 people at the event.
Trump left the United States to begin his trip on Friday.
On the campaign trail, Trump often accused Hillary Clinton of not having the "stamina" to be president.
"To be president of this country, you need tremendous stamina," Trump said in the first presidential debate. "You have to be able to negotiate our trade deals … with Japan, with Saudi Arabia."
Trump's first trip abroad as president is nine days long with stops in Saudi Arabia, Italy, Israel and Belgium.