(FILES) This file photo taken on December 12, 2015 shows Several Non Governmental Organisations (NGO)as they gather to form a human chain reading "+3oC SOS" on the Champs de Mars near the Eiffel Tower in Paris on the sidelines of the COP21, the UN conference on global warming. Donald Trump has decided to pull the United States out of the Paris climate accord, US media reported May 31, 2017, as the president kept the world guessing -- saying an announcement will come in the "next few days."An American pullout would deal a devastating blow to global efforts to combat climate change less than 18 months after the historic 196-nation pact was signed in Paris, fruit of a hard-fought agreement between Beijing and Washington under Barack Obama's leadership. / AFP PHOTO / ALAIN JOCARD