A White House official listening to President Donald Trump’s July 25 phone call with Ukraine’s president described the call as “crazy” and “frightening” and was “visibly shaken,” according to notes taken by the intelligence official who filed a formal whistleblower complaint after speaking with the official, and others.

ABC News has learned that the two-page memo, written by the whistleblower a day after Trump’s call, suggests that at least one aide to the president feared that Trump’s own words in the call were damning. According to a rough transcript of the call released by the White House, Trump asked Ukraine’s president Volodymyr Zelenskiy to launch an investigation into a political opponent, Democratic presidential candidate Joe Biden, and his son.

The notes were based on a brief conversation between the whistleblower and the White House official and described “highlights” from the president’s call.