Asked during the daily news briefing whether Obama has changed his mind, press secretary Jay Carney said, "I have no update on the president's personal views."
Carney said Biden's comments made "the same point that the president has made previously: that committed and loving same-sex couples deserve the same rights and protections enjoyed by all Americans, and that we oppose any effort to roll back those rights."
Duncan, the spokesman said, was asked about his personal views on the issue and he offered them.
"Obviously, this is an issue that many people have a view on and we respect the right of all people to have an opinion -- a personal opinion," Carney said.
Asked if he had any insight into Obama's personal view on the issue, Carney said: "I think the president is the right person to describe his own personal views. He, as you know, said that his views on this were evolving and I don't have an update for you on that."
Carney noted the administration opposes the Defense of Marriage Act and supports legislation to repeal it. The administration has stopped defending the constitutionality of a portion of DOMA in legal challenges.
Biden told NBC's "Meet the Press" he is "absolutely comfortable with the fact that men marrying men, women marrying women, and heterosexual men and women marrying another are entitled to the same exact rights, all the civil rights, all the civil liberties. And, quite frankly, I don't see much of a distinction beyond that."
He prefaced his remarks by saying: "I am vice president of the United States of America. The president sets the policy."
When asked if the Obama administration would come out behind same-sex marriage in a second term, Biden said, "I don't know the answer to that."
His remarks made Biden the highest-ranking White House official to embrace same-sex marriage, which is legal in six states and the District of Columbia but is unrecognized by the federal government.
The Obama administration has endorsed civil unions but not marriage for same-sex couples.
Continually pressed about Obama's view on same-sex marriages, Carney said, "I just don't have an update for you on the president's position.
"On his personal views, I can tell you that he is an absolutely committed support of LGBT [lesbian, gay, bisexual and transgender] rights. His record bears that out. It is an unparalleled record of support for LGBT citizens and their rights, and he's proud of it, and he'll run on it," Carney said. "And I think that it's important to remember when we talk about those accomplishments under this administration that they are far more than talking points: They are considerable, serious demonstrations of progress, important progress, progress that others would take away and reverse. This president's committed to not letting that happen."