WASHINGTON (AP) — President Donald Trump’s national security adviser says he did not listen to an audio recording of the killing of a Saudi journalist because he doesn’t speak Arabic.

John Bolton says that because he doesn’t speak Arabic, he doesn’t expect he would “learn any more” from listening to the tape than from reading a transcript. Bolton spoke to reporters Tuesday at the White House.

The audio recording quickly emerged as a key piece of evidence amid conflicting accounts of Jamal Khashsoggi’s murder at a Saudi Arabian consulate in October.

U.S. intelligence agencies have concluded that Saudi Crown Prince Mohammed bin Salman must have at least known about the plot to kill Khashoggi, prompting calls by many in Congress for the U.S. to take a tougher stance with the key Gulf ally.