In a video message marking International Day against Homophobia and Transphobia, U.N. High Commissioner for Human Rights Navi Pillay said homophobia and transphobia are no different to sexism, misogyny, racism or xenophobia.
"But whereas these last forms of prejudice are universally condemned by governments, homophobia and transphobia are too often overlooked," Pillay said.
History shows the "terrible human price" of discrimination and prejudice, the United Nations said in a release.
Pillay said statistics indicate homophobic hate crimes are rising in many parts of the world, and homosexuality is a criminal offence in more than 70 countries.
In a separate message, the chief of the Joint U.N. Program on HIV/AIDS said the stigma and discrimination faced by many lesbian, gay, bisexual or transgender people hinders an effective response to the disease.