President Donald Trump has wasted no time dismantling climate policies and promising a new era of fossil-fuel dominance, withdrawing the US from the Paris Agreement on his first day back in office.

U.S. withdrawal from the world's primary climate pact will have a bigger impact - in the U.S. and globally - than the country's first retreat in 2017, analysts and diplomats told Reuters.

President Donald Trump signed an executive order Monday directing the United States to again withdraw from the landmark Paris climate agreement, dealing a blow to worldwide efforts to combat global warming and once again distancing the U.