U.S. President Donald Trump on Tuesday announced he had fired a Department of Homeland Security official who has publicly contradicted the president’s unfounded claims about widespread election fraud.

Christopher Krebs, a former Microsoft Corp. executive, was nominated in 2018 by Trump as the first director of the Cybersecurity and Infrastructure Agency, which is known as CISA. His agency had declared the Nov. 3 election "the most secure in American history.”

In a tweet Tuesday evening, Trump said he was finished with Krebs.