"The United States has joined China to formally ratify the Paris agreement to curb climate-warming emissions, the world's two biggest economies said on Saturday, which could help put the pact into force before the end of the year.

U.S. President Barack Obama and Chinese President Xi Jinping submitted their plan to join the agreement to U.N. Secretary-General Ban Ki-moon, who is in China to witness the announcement.

Senior Obama adviser Brian Deese said the joint declaration should push other countries to formally join the agreement."

Valerie Volcovici, Ayesha Rascoe, Alister Doyle, and David Stanway report for Reuters September 3, 2016. [2]