President Donald Trump is expected to pull out of the Paris climate agreement, multiple news organisations are reporting, citing White House officials.
Administration sources told NBC News that Trump is leaning toward leaving the historic climate accord, but has not yet made a final decision.
The president himself said in a Wednesday evening tweet that he would officially announce his decision on the accord from the White House Rose Garden at 3:00 p.m. Thursday.
The news that Trump had made his decision was reported by The Associated Press, Fox News and Axios. The administration is reportedly still deciding how it will exit the agreement.
One option is to go through the established protocol for withdrawing from the accord, a process that would stretch out to the end of 2020, a White House official told Axios.
Trump could also declare the Paris Agreement a legal treaty, which would require the Senate to approve it, the sources said.
It is unclear whether Trump has the votes. Twenty-two of 52 Senate Republicans urged Trump to leave the accord in a letter last week.
A final option is to withdraw from an international treaty, the United Nations Framework Convention on Climate Change, which negotiated the Paris Agreement and other landmark climate deals.
More than two decades of climate diplomacy produced the Paris Agreement in December 2015.
The accord requires the 195 signatories - nearly every country in the world - to create national plans to reduce their greenhouse gas emissions in a bid to mitigate the impact of climate change.
Syria and Nicaragua are the only countries in the UN group that are not signatories.
The treaty aims to prevent global temperatures from rising by more than 2 degrees Celsius above pre-industrial levels.
Under President Barack Obama, the United States committed to reducing its greenhouse gas emissions by 26 to 28 per cent below 2005 levels by 2025.
The Obama administration also pledged $3 billion to a fund established to help developing nations meet their Paris Agreement goals, the largest donation announced to date.
Trump and many of his allies have long dubbed the Paris Agreement a "bad deal" for America. They say it forces the United States to make immediate sacrifices that will hurt the economy, while other countries such as China are allowed to put off action until later.
Sierra Club Executive Director Michael Brune said Trump had ceded the United States' role in directing climate change efforts to countries like China and India.
"Trump has abandoned the standard of American leadership, turned his back on the what the public and the market demand, and shamelessly disregarded the safety of our families just to let the fossil fuel industry eek out a few more dollars in profits," he said in a statement.
GOP already undermined Paris Agreement
Trump and Republicans have already begun chipping away at the Paris Agreement.
In his first 100 days in office, Trump sought to undermine many of the Obama-era policies that would allow the United States to meet its commitments to the accord.
He has set in motion the repeal of Obama's signature plan to cut greenhouse gas emissions from power plants, teed up a potential easing of automobile fuel efficiency standards, and rescinded a host of other energy industry regulations and guidelines in a bid to increase fossil fuel production.
A spending bill passed earlier this month to fund the federal government through September did not include any money for the fund that supports developing nations' treaty contributions.
A number of large American companies were among those advocating for staying in the Paris Agreement, including US energy giants Exxon Mobil and Chevron and their European peers Royal Dutch Shell and BP. The oil majors say the accord offers a framework for tackling global warming and gives the United States a role in steering the global response to climate change.
To be sure, these companies are big players in natural gas development and stood to benefit from Obama-era regulations that have already expedited the retirement of some coal-fired plants and would likely continue that trend.
But even some coal producers like Cloud Peak Energy and Peabody Energy argued the United States should remain a party in order to negotiate coal's future in the global energy mix.
White House schism
The issue had reportedly split the Trump administration into "stay" and "leave" camps. The two sides had quibbled over whether language in the text of the Paris Agreement allowed the United States to reduce its commitment.
The stay camp included Secretary of State Rex Tillerson and Energy Secretary Rick Perry, as well as Trump's daughter and assistant Ivanka Trump and her husband, Jared Kushner, a White House senior advisor.
They argued Trump has the authority to revise the country's contributions to make them less ambitious.
The leave camp was led by White House chief strategist Steve Bannon and Environmental Protection Agency Administrator Scott Pruitt.
They maintained that the Paris Agreement only allowed for an upward revision of a signatory's commitments and efforts to walk back US goals could lead to legal challenges by environmentalists.
The White House had signaled Trump would make a decision prior to meeting last weekend with leaders of G-7 nations, but later said the announcement would not come until after the summit.
Trump telegraphed his expected decision at the meeting by refusing to endorse the Paris Agreement.