The voice of Osama Bin Laden is ringing out across radio and television stations after more than a year of silence.In a recorded message authenticated by the CIA, the al Qaeda leader has warned that more attacks are being prepared against the US. However, he says his group is open to a truce with Washington if American soldiers are withdrawn from Iraq and Afghanistan.It was the first recorded message from Bin Laden since 2004, when he offered a similar truce to Europe.The al Qaeda leader said he was willing to respond to US public opinion in favour of pulling troops out of Iraq. However, White House spokesman Scott McClellan said: “We do not negotiate with terrorists, we put them out of business. The terrorists started this war and the president made it clear that we will end it at a time and place of our choosing. We continue to pursue all those who seek to do harm to the American people, and to bring them to justice.” Bin Laden’s message was first played on the TV channel Al Jazeera, which has not revealed how it obtained the tape. A reference in the audio is said to indicate it was recorded earlier this month.