Mr. Obama was speaking in an interview with Australian television broadcast Thursday ahead of a trip to Asia next month.
Asked specifically about China's commitment to curbing greenhouse emissions, Mr. Obama told the Australian Broadcasting Corp. that the impulse of the Asian giant's leaders at the moment was to let developed countries deal with the problem first.
He said that "the point we have tried to make is that we can't allow China to wait."
China and the United States are among the world's largest emitters of the gases that cause global warming, though Mr. Obama said "no two countries can dictate a solution" to the problem.
Also in the interview, President Obama reaffirmed his plans to start withdrawing U.S troops from Afghanistan in 2011.
The president said of Afghanistan that the United States and its allies "can't be there in perpetuity."
Mr. Obama said that he did not agree that the situation in Afghanistan was getting worse, saying the Taliban's momentum had been "blunted" since he came to office.
But winning the nearly nine-year-old war remained a difficult task, he said.