Former U.S. President Bill Clinton turned to rocker Bono for advice when he was trying to solve a visa headache over Sinn Fein leaders MARTIN MCGUINNESS and GERRY ADAMS. The U2 frontman admits he was surprised when the then-President asked for his opinion - and he's glad Clinton ignored it. Speaking to rock magazine Rolling Stone, Bono reveals, "Bill Clinton once rang us, because he was collecting opinions on whether he should give Martin MCGuinness and Gerry Adams a visa into the United States. "I thought, 'These people have put bombs in supermarkets, and many innocent people have lost their lives,' so I said, 'No. Don't dignify them.'" "And he said, 'But shouldn't you always talk to people?' And I said, 'Yeah, but you dignify them.' "I was wrong. Clinton did exactly the right thing in talking to the Provisional IRA and other extremist elements." And Bono is urging the current U.S. government to do the same with terrorist groups they're at war with. He adds, "They have to do the same, in my opinion, with Hamas, and they have to do the same with Al Qaeda. You have to involve them in dialogue." Sinn Fein is the political wing of the Irish Republican Army (IRA).