Watch: Obama calls for urgent world action on climate change

US President Barack Obama says the world "has to step up" to help combat climate change and adds that the United Nations will continue to press other countries to take action. Obama commented on Tuesday following an Oval Office meeting with U.N. Secretary-General Ban Ki-moon. The UN leader added that he counts on the President's continued leadership on climate change issues as they enter the coming months leading up to the UN Climate Change conference in Paris. Obama is expected to attend the annual meeting of the U.N. General Assembly in September.