The United States and China have agreed a deal to tackle climate change, formally ratifying the Paris agreement, ahead of the G20 summit in Hangzhou.
“Just as I believe the Paris agreement will ultimately prove to be a turning point for our planet, I believe that history will judge today’s efforts as pivotal,” the US president, Barack Obama said on Saturday at a press conference with his Chinese counterpart Xi Jinping.
"Where there is a will and there is a vision and where countries like China and the United States are prepared to show leadership and to lead by example, it is possible for us to create a world that is more secure, more prosperous and more free than the one that was left for us,” he added.
"Despite our differences on other issues we hope that our willingness to work together on this issue will inspire greater ambition and greater action around the world."
“Our response to climate change bears on the future of our people and the well-being of mankind,” Mr Xi was quoted by AP as saying.