US sports network ESPN pulled Hank Williams Jr.'s theme song from its Monday Night Football broadcast in a rebuke to the country music star for comments Monday comparing US President Barack Obama to Adolf Hitler. Williams apologized for the comments on Tuesday.Williams, a Republican, had appeared on a Fox News' morning television show FOX and Friends on Monday, and was asked which of his party's presidential candidates he liked.RELATED:UK wax museum puts guard next to Hitler figure Kanye West compares himself to Hitler In an apology posted to his website Tuesday, Williams admitted that his comment was "dumb," adding, "Sorry if it offended anyone."In an earlier statement, Williams admitted that his comment was "extreme...I have always respected the office of the President."Williams made his inflammatory statement on Fox News talk show Fox & Friends. Grousing about Obama and Boehner playing golf together over the summer, Williams said it was like "Hitler playing golf with Binyamin Netanyahu."Elsewhere during his appearance, Williams referred to Obama and Vice President Joe Biden as "the enemy."Williams' comments were enough to make ESPN yank its regular opening, which features Williams singing "All My Rowdy Friends," from this week's Monday Night Football. "We are extremely disappointed with his comments, and as a result have decided to pull the open from tonight's telecast," ESPN said in a statement.