WASHINGTON (AP) — A federal judge on Monday dismissed a lawsuit from a former White House official who had challenged a congressional subpoena in the impeachment inquiry involving President Donald Trump.

Charles Kupperman, a former deputy national security adviser, had asked a court to decide whether he had to comply with the subpoena given that the White House had instructed him and other officials not to appear before a congressional investigation into Trump's interactions with Ukraine.

U.S. District Judge Richard Leon said in an opinion Monday that the case was moot since the House has withdrawn its subpoena and stated in court that it doesn't plan to issue one again.