Donald Trump's national security adviser reportedly mocked the US president and called him a "kindergartner" during a private dinner.
General H.R. McMaster is said to have made the disparaging remarks about his boss during a meeting with Oracle CEO Safra Catz in July.
During the meeting General McMaster mocked Mr Trump, calling him an "idiot" and a "dope", adding he had the intelligence of a "kindergartner", five sources told BuzzFeed News.
The general is also reported to have criticised other members of Mr Trump's administration, including secretary of defense James Mattis, former strategist Steve Bannon and Mr Trump's son-in-law Jared Kushner.
General McMaster, who serves as Mr Trump's top adviser on national security matters, also reportedly told a sixth source that the president lacked the intelligence to understand the matters before the National Security Council.
Ms Catz, who has been touted as a future White House staff member, and Mr Trump's administration have robustly denied the comments.
“Actual participants in the dinner deny that General McMaster made any of the comments attributed to him by anonymous sources,” said Michael Anton, a spokesman for the National Security Council.
It is not the first time a member of the Trump administration is reported to have made such comments about the president's intelligence.
Profile | Lt General HR McMaster
Last month it was claimed secretary of state Rex Tillerson referred to Mr Trump as a "moron" during a meeting at the Pentagon.
When the reports emerged, Mr Tillerson repeatedly refused to answer when asked whether he had made the comments.
Republican senator Bob Corker has previously likened the White House to "adult daycare".