President Donald Trump’s Senior adviser Stephen K. Bannon has exited his role on President Donald Trump’s National Security Council, claiming that his mission is complete.

“Susan Rice operationalized the NSC during the last administration. I was put on to ensure that it was de-operationalized,” Bannon said in a statement to the Wall Street Journal.

The council suffered a tumultuous transition after Trump’s first National Security Adviser Gen. Michael Flynn resigned less than a month after he took office and was replaced by Lt. Gen. H.R. McMaster.

“General McMaster has returned the NSC to its proper function,” Bannon said in his statement. Other sources told reporters that Bannon was part of the council to monitor Flynn’s activity in the early days of the Trump administration.