WASHINGTON (CNN) -- President Donald Trump is set to announce his decision to withdraw the US from the Paris climate accord Thursday, a major step that will fulfill a campaign promise while sparking global outcry.
The White House began informing members of Congress Thursday afternoon that Trump planned to pull out of the US from the landmark agreement, according to a congressional source.
Trump will speak during a 3 p.m. ET event in the White House Rose Garden.
In talking points delivered to Trump's allies, the White House characterized the Paris agreement as a job killer that placed undue burdens on American taxpayers.
"The Paris Accord is a BAD deal for Americans, and the President's action today is keeping his campaign promise to put American workers first," the talking points read. "The accord was negotiated poorly by the Obama administration and signed out of desperation. It frontloads costs on the American people to the detriment of our economy."
Trump and Vice President Mike Pence were calling lawmakers, including House and Senate leaders, in the hours leading up to the announcement to get input on his climate decision, a Republican source said.
In triggering the official withdrawal process, Trump will spark a lengthy process that won't conclude until November 2020 -- the same month he's up for reelection.
The President campaigned against the climate agreement as a candidate, and those close to him suggest he's ready to fulfill those promises to remove the US from the 195-country deal. The move would isolate the United States in a global effort to curb the warming of the planet, and leave an opening for countries like China to fill the leadership void.
Pressure to remain in the Paris accord has been intense, however, including from some of Trump's closest aides.
But a person familiar with Trump's thinking said the President was convinced he needed to withdraw from the pact, and there was little chance of talking his out of it.
The uncertainty over Trump's decision has lent the Paris announcement a reality show-like air, with Thursday's unveiling a finale to a months-long debate that has split members of the President's inner circle and led to deep consternation from global allies.
Trump, a former reality star himself, advertised the announcement in a tweet late Wednesday. Earlier in the day, he told reporters he was "hearing from a lot of people both ways."
On Thursday morning, senior administration officials said they still believed Trump planned to announce a withdrawal from the accord but would not reveal the precise mechanism the US would utilize to execute the decision.
Trump would have several options, including triggering a years-long withdrawal process or taking the more drastic step of removing the US from the United Nations climate treaty. He could also declare the Paris agreement a treaty that requires Senate approval, which isn't likely to come from the Republican-controlled body.
Lawyers and other administration aides have planned a withdrawal announcement, but recognize Trump has changed his mind at the last minute previously on important decisions where outside forces are pressuring him to moderate his position.
As news emerged Wednesday that Trump planned to quit the Paris deal, business leaders and foreign heads-of-state began castigating the decision as a woeful abandonment of US leadership. Elon Musk, the chief executive of Tesla, said he would resign from White House business councils if Trump followed through. Apple CEO Tim Cook also urged Trump to reconsider.
Inside the West Wing, attempts to sway Trump's thinking also continued apace. Trump's daughter and senior adviser, Ivanka, has worked to ensure her father heard pro-Paris voices over the last several months, and has continued to press for a decision short of a full withdrawal.
Ivanka Trump and her allies, including Secretary of State Rex Tillerson and Trump's chief economist Gary Cohn, have pressed Trump to alter the US commitments to the Paris agreement without fully pulling out of the accord.
A Republican familiar with Trump's decision-making said the expected announcement could include some attempts to satisfy his daughter's point of view, but didn't specify what that might include.
But anti-Paris voices, led by chief strategist Steve Bannon and EPA administrator Scott Pruitt, have appeared to won out. In conversations with his advisers, Trump has cited the affect a withdrawal would have on the states where he won by the largest margins, including in the Rust Belt and the western plains.
That's a reflection of Trump's "America First" governing policy, which he's sought to bolster since taking office. Trump was pressured heavily by his foreign counterparts during last week's G7 meetings in Sicily to remain in the deal, but his advisers say he felt little obligation to concede to that point of view.
On Wednesday, global figures began reiterating their own commitment to the Paris deal as Trump prepared to withdraw. Chinese premier Li Keqiang, visiting Germany, said his country would remain committed to combating climate change, despite US moves.
And European Commission President Jean-Claude Juncker declared Europe was ready to act as a global climate leader in the US absence.
"The vacuum that would be created has to be filled, and Europe has aspirations for a natural leadership in this whole process," he said in Berlin.