UNITED NATIONS - President Barack Obama Tuesday urged world action to fight climate change, saying a failure to tackle the problem could lead to an irreversible catastrophe in years to come.

Obama, speaking at a U.N. summit on global warming, outlined his administration's actions to combat climate change in the last eight months but did not offer any new U.S. proposals that could help lead to a breakthrough in talks for a new international pact to fight global warming.

Our generation's response to this challenge will be judged by history, for if we fail to meet it - boldly, swiftly, and together - we risk consigning future generations to an irreversible catastrophe, Obama said, according to prepared remarks.

(Reporting by Jeff Mason; editing by Andrew Quinn)