Vice President Joseph R. Biden Jr. said on Sunday that he was “absolutely comfortable” with same-sex marriages and was heartened by their growing acceptance across the country, a position that moves well beyond the “evolving” views that President Obama has said he holds on the issue.

The comments, which aides described as the off-the-cuff views of a vice president not known for fidelity to a script, sent the White House scrambling to clarify that Mr. Biden was not articulating an official change in policy, a reaction that highlighted the administration’s unease over the subject.

In an interview on NBC’s “Meet the Press,” Mr. Biden invoked some of the same language that advocates of same-sex marriage use, speaking of family, equality and love.

“I am absolutely comfortable with the fact that men marrying men, women marrying women and heterosexual men and women marrying one another are entitled to the same exact rights, all the civil rights, all the civil liberties,” Mr. Biden said, while noting that the president, not he, sets policy on such matters.