The actor left fans of the medical drama stunned when his doctor character, Lawrence Cutner, committed suicide.







He then announced he'd taken a position as the associate director in the White House's Office of Public Liaison & Intergovernmental Affairs - a role similar to the one he held as a volunteer in Barack Obama's campaign to become President.







Penn moved to Iowa to work exclusively for Obama during the Hollywood writers strike in 2007, and admits he has wanted to do more for the US leader ever since.







But he insists this won't signal the end of his acting career.







Calling in to Los Angeles radio station KOST 103.5 on Wednesday morning, Penn said, "I'm not retiring from acting... It's not a Joaquin Phoenix-style walking away (and) never coming back.







He adds, "I still have a passion for it. But for the time being, I won't be acting."







Of his new public service role, the actor reveals, "I got to know the President and some of the staff during the campaign and had expressed interest in working there, so I'm going to be the associate director in the White House office of public liaison.







"They do outreach with the American public and with different organisations. They're basically the front door of the White House. They take out all of the red tape that falls between the general public and the White House."