Despite statements from his advisers proclaiming the summit's nonbinding agreement a great step forward, Obama says it didn't take the steps necessary to combat the effects of climate change.
The accord Obama helped broker last week urges major polluters to make deeper emissions cuts but does not require them to do so. Still, despite its shortcomings, Obama says the agreement was better than doing nothing.
"I think that people are justified in being disappointed about the outcome in Copenhagen," Obama said. "It didn't move us the way we need to."
He added: "I make no claims, and didn't make any claims going in, that somehow that was going to be everything that we needed to do to solve climate change… My main responsibility here is to convince the American people that it is smart economics and it is going to be the engine of our economic growth for us to be a leader in clean energy."
At the summit last week, Obama had said there had been "a meaningful and unprecedented breakthrough."
Obama made his remarks today in an interview with PBS NewsHour.