Democrats, environmentalists blast idea US could leave the Paris accord Trump's likely decision has been condemned by environmental groups.

 -- President Trump's likely decision to withdraw from the Paris climate accord has been condemned by environmentalists and some Democrats, who view the deal as critical to the health and survival of our planet.

An official who spoke to ABC News about Trump's likely decision cautioned that nothing is final until the president announces it, and that the White House is now working out a way to roll out and explain the reasons behind his decision.

If Trump does pull out of the 2015 Paris accord on climate change, the United States would become one of only three nations in a U.N. climate group not to be signed onto the deal.

As of this month, the December 2015 deal has been signed by all but two of the 197 countries in the United Nations Framework Convention on Climate Change (UNFCCC). Only Syria and Nicaragua remain.

Senator Ed Markey, D-Mass., wrote on twitter that the likely decision would hurt America's standing in the world.

"Pulling out of #ParisAgreement is a massive moral, economic & leadership failure for Trump admin. Loss of business, jobs, & intl standing," Markey wrote.

Democratic Leader Nancy Pelosi released a statement condemning the potential move, one which she said favors big energy over the environment and allows other countries to take the lead.

"President Trump’s decision to pull the United States out of the Paris Climate Accord is a stunning abdication of American leadership and a grave threat to our planet’s future," Pelosi wrote. "In walking away from this agreement, the President is denying scientific truths, removing safeguards that protect our health and our environment, protecting polluters and their dirty energy agenda, and threatening our national and global security."

Michael Brune, executive director of the Sierra Club, a prominent environmental advocacy group, released a statement saying that "our grandchildren will look back on with stunned dismay at how a world leader could be so divorced from reality and morality" in response to Trump's likely decision.

"This is a decision that will cede America’s role internationally to nations like China and India, which will benefit handsomely from embracing the booming clean energy economy while Trump seeks to drive our country back into the 19th century," Brune wrote.

Rhea Suh, president of the Natural Resources Defense Council, an environmental law advocacy group, called the likelihood of Trump's decision a wrong turn.

“If true, it is a reckless and foolish mistake, and our kids will pay the price," Suh wrote on Twitter.

Conservative think tank, The Heritage Foundation disagreed, writing that Trump was correcting Former President Obama's course, which they said "displayed contempt for the role of Congress and the democratic process in treaty making."

And Elon Musk, CEO of Tesla and SpaceX, said Wednesday he'll step down from Trump's advisory councils if he decides to withdraw from the Paris climate agreement.

"Don't know which way Paris will go, but I've done all I can to advise directly to POTUS, through others in WH & via councils, that we remain," Musk tweeted. "Will have no choice but to depart councils in that case."