According to Obama, "it would be up to future generations of Americans to implement meaningful reform," ABC added.
"First of all, I've been very clear about my belief that same-sex couples have to be treated before the eyes of the law the same way as heterosexual couples," he told MTV's Sway Calloway. "I think that's the right thing to do. It's based on my personal experience, seeing loving couples who are committed to each other, raising kids and are just outstanding people," he added. "And I was supportive of civil unions, but they taught me, if you're using different words, if you're somehow singling them out, they don't feel true equality."
Over the years, Obama has held different opinions on the subject. In 1996, he supported gay marriage, but held a different opinion in 2004.
“What I believe is that marriage is between a man and a woman … What I believe, in my faith, is that a man and a woman, when they get married, are performing something before God, and it’s not simply the two persons who are meeting,” he said when running for the Senate.
In 2008, he supported civil unions, but did not support gay marriage.
"My feelings about this are constantly evolving. I struggle with this. At this point, what I’ve said is, is that my baseline is a strong civil union that provides them the protections and the legal rights that married couples have,” he said just two months after telling liberal bloggers that he was "unwilling to sign on to same-sex marriage."
In May, however, he reverted to his 1996 position and came out in support of gay marriage, causing a backlash from black churches.
Obama rejected the idea of federal legislation mandating gay marriage and said that it should be decided at the state level.
"For us to try to legislate federally into this area is probably the wrong way to go," he said.
One of those in the audience was a young man identified as "Tucker," who said he was from Washington State.
"I love having a president in the White House who can go on MTV and say that he thinks gay and lesbian people should get married, that's great," he said. "But the fact is, it's been four years and the Defense of Marriage Act is still on the books, and I don't think the conversation should be left to the states," he added.
He said that he was "very afraid" that Washington voters "are going to vote on my rights to marry in a way that I don't think is right."
Supporters of Washington's ballot measure, known as Referendum 74, have raised nearly $11 million to finance a well-oiled campaign designed to convince voters that gay marriage is necessary, even though the state already has an “Everything But Marriage” law that gives same-sex couples full legal rights.