The spokesman for the National Security Council says President Trump’s “disturbing” and repeated attempts to undermine the U.S. intelligence community prompted him to resign last week, the Huffington Post reports.

“In a scorching Washington Post column published Monday, Edward Price … pointed to several instances in which he said Trump had questioned the integrity of U.S. intelligence agencies, including the president’s tepid response to reports that Russia hacked U.S. officials in an attempt to influence the 2016 presidential election.”

But the “final straw” was Trump’s decision last month to make chief strategist Steve Bannon — whom Price calls “a media champion of white nationalism” — a member of the National Security Council.