After years of evolving on the issue,US President Barack Obama said on Wednesday he believes same-sex marriage should be legal. It is important for me to affirm that I think same-sex couples should be able to get married, Obama said in an interview with ABC. Obamas comments marked the first time a US president had publicly expressed support for gay marriage,and his position was hailed by Democrats and gay rights groups. New Zealand Prime Minister John Key said his government may consider allowing it at some stage. However,conservative Christian and Muslim leaders decried his stand,and Australian PM Julia Gillard said she remains opposed. Meanwhile,on Thursday,Obamas campaign released a video titled Mitt Romney: Backwards on Equality,attacking Romneys opposition to gay marriage or union.