"It is not genetic. It is not congenital. It is behavior," said Museveni in a speech at the rally. "That's why I said I am going to sign the bill because I am convinced, with the available information, that these people are not born like that. They just learn and they can unlearn what they have learned."
The U.S. has threatened to withhold about $400 million in aid from Uganda due to the country's anti-gay laws. Several European nations have already halted about $122 million in funds. Museveni was defiant towards these actions and said his country does not need Western money.
"When you hear these Europeans saying they are going to cut aid ... we don't need aid in the first place ... A country like Uganda is one of the richest on earth," he said.
Ugandans live on about $450 per year, and the country relies heavily on foreign aid to run.
Museveni, who has been in power since 1986, plans to run for office again in 2016.