At the Sept 25 event, Sir Elton said that the abstinence programs that the Bush administration was banking on were nothing but a tragic waste of money.
He also urged people not to follow such programs.
'They've made a grave error in giving millions to abstinence programs,' the New York Daily News quoted him as saying.
'They don't work. They were told in the beginning that it wouldn't work. It's a tragic waste of money. Please don't listen to those idiots. God almighty,' he added.
Elton also criticised South African President Thabo Mbeki for supporting his health minister's notions that garlic beetroots, lemon and olive oil were better than antiretroviral medicines in treating AIDS.
'There are some weird people in the world — what can I say?' he said, 'I would just tell them, 'Don't let the AIDS crisis get lost.'
The singer revealed that his foundation's latest target would be the Caribbean, where 'men who have sex with men (are) a highly stigmatised group, especially among reggae singers.'