Under the accord's rules, the United States will formally exit in one year.

The United States formally has notified the United Nations that it was withdrawing from the Paris climate accord, making the world's largest economy the sole outlier from the agreement.

President Donald Trump says that the United States could "conceivably" return to the Paris climate accord, although he stopped short of signalling any move in that direction.

A group of US states, cities, businesses and universities said Saturday they are still committed to curbing global warming even as US President Donald Trump’s administration is walking away from the Paris climate accord.