COPENHAGEN — Developing countries raised the stakes Thursday for any successful outcome of the U.N. climate talks, demanding that the international community provide $200 billion to mitigate global warming in the poorest nations.

They also issued a challenge to U.S. President Barack Obama, who in his acceptance speech for the Nobel Peace Prize spoke in Oslo about climate change as a security issue.

Obama must prove he really deserved the award by agreeing to maintain and enforce the 1997 Kyoto Protocol and its provisions on emissions and paying to combat climate change, rather than creating a new Copenhagen Protocol, something the U.S. and U.N. say is not going to happen, developing countries said.