President Donald Trump's administration has been contacting U.S. energy companies to ask them about their views on the U.N. global climate accord, according to two sources with knowledge of the effort, a sign Trump is reconsidering his 2016 campaign pledge to back out of the deal.

The sources, who asked not to be named because they are not authorized to speak publicly on the subject, said many of the companies reached by the administration had said they would prefer the U.S. remain in the pact, but would also support reducing the U.S. commitments in the deal.

The accord, agreed by nearly 200 countries in Paris in 2015, would limit planetary warming in part by slashing carbon dioxide and other emissions from the burning of fossil fuels. As part of the deal, the U.S. committed to reducing its emissions by between 26% and 28% below 2005 levels by 2025.

The sources did not name the companies contacted.

One of the sources said the companies were "publicly traded fossil fuel companies," and added the White House would consider their input in making a decision on the Paris accord shortly. The source said the White House has been leading the discussions with the fossil fuel companies and the State Department, which represents the United States in climate negotiations, had not taken part.

A White House official declined to comment.

Trump has called climate change a hoax and vowed during his campaign for the White House to pull the U.S. out of the Paris deal, claiming it would be too costly for the U.S. economy.

Since being elected he has been mostly quiet on the issue. In a New York Times interview in November he said he would keep an open mind about the Paris deal. He and members of his family and inner circle also met with climate change advocate and former Vice President Al Gore in December.

Officials for Exxon Mobil, ConocoPhillips, Chevron, Peabody Energy Corp and others did not immediately comment when asked about whether they had been contacted by the White House about the Paris accord.

But several, including Exxon Mobil and ConocoPhillips, have expressed public support for the pact.