US President Barack Obama is urging an end to psychiatric therapies that seek to change the sexual or gender orientation of gay, lesbian and transgender youth, the White House said.

The White House statement, released Wednesday, was in response to a petition calling for Obama to back a law to ban conversion therapy, which is supported by some socially conservative organizations and religious doctors.

The petition was started following the December suicide of 17-year-old transgender youth Leelah Alcorn, who died after her parents forced her to attend conversion therapy, pulled her out of school and isolated her in an attempt to change her gender identity.