U.S. Secretary of State Rex Tillerson, who was fired by President Donald Trump on Tuesday, said he was delegating all of his responsibilities to the State Department’s No. 2 official and that he would leave office at the end of the month, Reuters reported.

“What is most important is to ensure an orderly and smooth transition during a time that the country continues to face significant policy and national security challenges,” Tillerson told reporters in a packed briefing room at the State Department.