US President Donald Trump notified Congress on Friday that he is firing the inspector general of the country’s intelligence community who was involved in triggering an impeachment probe of the president last year.

In a letter to key lawmakers, Trump said that he planned to remove the official, Michael Atkinson, in 30 days and said, “it is vital that I have the fullest confidence in the appointees serving as inspectors general.”

“This is no longer the case with regard to this inspector general,” he said.

Atkinson, a Trump appointee, had determined that a whistleblower’s report was credible in alleging the president abused his office in attempting to solicit Ukraine’s interference in the 2020 US election for his political benefit.

According to a Justice Department legal opinion, Atkinson was also concerned that Trump potentially exposed himself to “serious national security and counter-intelligence risks” when he pressed Ukrainian President Volodymyr Zelenskiy to investigate Democratic presidential hopeful Joe Biden and his son during a July 25 phone call.

In February this year, Trump suggested that the Pentagon should review the conduct of a former White House national security aide who played a central role in the Democrats’ impeachment case and potentially consider disciplinary action against him.

Earlier, the president has already been sharply criticized for pushing out Alexander Vindman and others who crossed him in the impeachment hearings.

After the Senate acquitted Trump of both charges, Senate Majority Leader Mitch McConnell would not say at a press conference whether he thought what Trump did was wrong, or if he agreed with some Republican colleagues it was inappropriate for a president to ask a foreign power to probe a political rival.

Last year, on December 18, President Trump was formally impeached in a historic vote in the House of Representatives.