WASHINGTON, June 1 (Reuters) - President Donald Trump on Thursday will announce his decision on whether to keep the United States in a global pact to fight climate change, as a source close to the matter said he was preparing to pull out of the Paris accord.
Trump said in a Twitter post on Wednesday night that he would make the announcement at 3 p.m. EDT (1900 GMT) on Thursday in the White House Rose Garden, ending his tweet with "MAKE AMERICA GREAT AGAIN!"
A U.S. withdrawal would deepen a rift with U.S. allies and put the United States in the same league as Syria and Nicaragua as the world's only non-participants in the landmark 195-nation accord agreed upon in Paris in 2015.
Scientists have said a U.S. withdrawal from the deal could speed up the effects of global climate change, leading to heat waves, floods, droughts, and more frequent violent storms.
During his 2016 presidential campaign, Trump blasted the accord, saying it would cost the U.S. economy trillions of dollars with no tangible benefit.
The Republican vowed at the time to "cancel" the Paris deal within 100 days of becoming president on Jan. 20, part of an effort to bolster U.S. oil and coal industries.
Since taking office, however, he has come under pressure from advisers, close allies, corporate CEOs, Democrats and some fellow Republicans to keep the United States in the accord - causing him to rethink and delay his decision.
Some executives from coal companies have weighed in, arguing the U.S. should stay in with reduced emissions cuts targets, with an eye toward ensuring that Washington keeps some influence over the future of the global energy mix.
The source, speaking on condition of anonymity, said Trump was favoring an exit, however, and was working out terms of the planned withdrawal with U.S. Environmental Protection Agency Administrator Scott Pruitt, an oil industry ally and climate change doubter.
The pact was the first legally-binding global deal to fight climate change. Virtually every nation voluntarily committed to steps aimed at curbing global emissions of "greenhouse" gases. These include carbon dioxide generated from burning of fossil fuels that scientists blame for a warming planet, sea level rise, droughts and more frequent violent storms.
The United States, under former President Barack Obama, had committed to reduce its emissions by 26 percent to 28 percent from 2005 levels by 2025. (Reporting by Valerie Volcovici, Timothy Gardner, Jeff Mason, and Roberta Rampton; Editing by Nick Zieminski)