Speaking around 1pm ET, Obama said he had just met with Zhang Gaoli, China’s vice premier, who is the highest ranking Chinese official to attend Tuesday’s climate summit.

“As the two largest economies and emitters in the world, we have a special responsibility to lead,” Obama said. “That’s what big nations have to do.”

While emphasising that the US recognises its role “in creating this problem”, Obama drew attention to the fact that the US is no longer the world’s largest emitter.