From the Guardian, Sarah Boseley jotted down the following notes from the speeches.
"This is a tough economic environment. Right now there isn't enough money to simply treat our way out of this epidemic," he said.
"If we keep spending our resources in exactly the same way we do today, we will fall further behind in our ability to treat everyone."
Gates cited male circumcision, which a major trial four years ago showed could reduce the chances of a man contracting HIV by 60% – although it is as yet not proven to protect women.
Clinton, a former two-term US president, called for better use of the limited funds available in a separate speech warning that excessive resources went on bureaucracy, unnecessary trips and unread reports.
"In too many countries, too much money pays for too many people to go to too many meetings and get on too many aeroplanes to do too much technical assistance," he said. "Too much money is spent on reports that sit on shelves. Every dollar we waste a day puts a life at risk."
He called on America to lead the way and for all countries "to do some soul-searching … and actually spend the money on the people it was meant to help instead of the apparatus in the country in question".
Clinton said he did not want to blame anybody. "I was president for eight years and I had no idea it was as bad as it was," he said. But, he added: "We can fix this."