Presidents promise that Paris deal will be approved

China and the United States announced on Thursday that they will sign the Paris climate agreement on April 22, as the world's two largest greenhouse gas emitters continue to strengthen their cooperation to combat climate change.

The two countries have pledged to take their respective domestic steps in order to join the agreement as early as possible.

The presidential announcement on climate change was released just hours before a bilateral meeting in Washington between President Xi Jinping and US President Barack Obama on the sidelines of the 4th Nuclear Security Summit.