Tehran has put pressure on media outlets that support the opposition movement that grew out of contested 2009 presidential elections.
Dozens of Iranian journalists remain behind bars following a crackdown on dissent. The clerical regime is harsh on press freedoms in the Islamic republic and banned foreign journalists from covering post-election violence last summer.
Ehsan Qazizadeh, an official with the Ministry of Culture, said media outlets that aren't supportive of the regime are considered illegal.
"Those publications that insist on publishing announcements and pictures of the leaders of sedition will be banned according to the law," he was quoted by the official Islamic Republic News Agency as saying.
He added that media outlets that didn't support the regime would be cut off from federal funding.