Mr Soros has thrown his weight behind a push by Guatemalan President Perez Molina, who recently declared that prohibition should be abandoned.

BBC: Davos 2013: Soros calls for new strategy on drugs

President Barack Obama, who said during his 2008 campaign that marriage was "between a man and a woman, " in May declared his support for same-sex marriage, and the administration has now put its weight behind supporters of gay marriage before the Supreme Court.

CNN: America is at a crossroads on gay rights