U.S. President-elect Donald Trump said he is keeping an open mind on whether to pull out of a landmark international accord to fight climate change, in a softening of his stance toward global warming.

Media reports quote say Trump thinks there is “some connectivity” between human activity and global warming, despite previously describing climate change as a hoax.

A source on Trump’s transition team said earlier this month that the New York businessman was seeking quick ways to withdraw the U.S. from the 2015 Paris Agreement to combat climate change.

But asked recently whether the U.S. would withdraw from the accord, the Republican said: “I’m looking at it very closely. I have an open mind to it.”

A U.S. withdrawal from the pact, agreed to by almost 200 countries, would set back international efforts to limit rising temperatures that have been linked to the extinctions of animals and plants, heat waves, floods and rising sea levels.

Trump, who takes office on January 20, also said he was thinking about climate change and American competitiveness and “how much it will cost our companies,” he said, according to a tweet by a Times reporter in the interview.

Two people advising Trump’s transition team on energy and environment issues said they were caught off guard by his remarks.

A shift on global warming is the latest sign Trump might be backing away from some of his campaign rhetoric as life in the Oval Office approaches.