The White House said on Thursday that the United States is open to holding talks with Iran about stabilizing Iraq after the Islamic republic responded to prior offers from Washington for a dialogue. White House spokesman Scott McClellan said U.S. Ambassador to Iraq Zalmay Khalilzad was authorized to speak to the Iranians about issues specific to Iraq. McClellan said this channel of communications was narrow, with only Iraq to be discussed, and that the nuclear issue was one for the U.N. Security Council. "Our ambassador is authorized to talk with leaders in Iran, but it's to reiterate to them and express our concerns that we have about their involvement inside Iraq," McClellan said, rejecting any characterization of it as opening a dialogue with Tehran.