Barack Obama has said that society is "moving in the right direction" on LGBT rights in response to a question from a transgender student.
The US president was accused of not taking not taking seriously the lives of non-binary people - those who do not identify as either male or female.
Maria Munir, 20, from Watford, broke down in tears as they came out as publicly as transgender - something they had not yet told their parents.
They told Mr Obama that the UK did not recognise non-binary people under the equality act, meaning they have "no rights" in the face of discrimination.
Mr Obama said that the US was "taking a lot of serious steps" to address LGBT issues in the federal government.
He also praised Mr Cameron as "ahead of the curve" on the topic.
"You should feel encouraged," he said. "Social attitudes have changed faster on this issue than I've seen on any other issue.
"It doesn't feel fast enough to you or for those who are impacted, and that's good. You shouldn't feel satisfied, you should keep pushing.
"But I think the trend lines are good on this. We are moving in the right direction."
Munir later said that they were expecting a conversation with their parents after coming out to them via a message on the world stage.
"I'm sorry mum and dad," they said, adding: "I'm sure they'll have lots of things to say to me when I get home".