U.S. Environmental Protection Agency Administrator Scott Pruitt holds up a miner's helmet that he was given after speaking with coal miners at the Harvey Mine on April 13, 2017 in Sycamore, Pennsylvania.

Pruitt's comment reflected language frequently used by climate change skeptics, who acknowledge that the climate is changing, but say such shifts in global temperatures have occurred throughout the course of Earth's history, and cannot be directly attributed to human activity.

Pruitt, however appeared hedge by saying Trump believes "the climate changes." That is not the same as backing the EPA's conclusion, reached prior to Pruitt's appointment, that carbon dioxide emissions from human activity are the primary cause of global warming.

"Well, frankly, George, I think the whole question is an effort to get it off the point and the issue of whether Paris is good for this country or not. And the president has indicated the climate changes," Pruitt said.

Environmental Protection Agency Administrator Scott Pruitt on Sunday refused to say whether he knows if President Donald Trump believes in climate change.

Pruitt, who advised Trump to leave the Paris Agreement, reiterated his claim that his discussions with Trump focused on the economic impact of the treaty on the U.S. economy and not the president's views on global warming.

In media appearances, several of the president's surrogates have also evaded the question, following Trump's decision to exit the international accord aimed at mitigating the effects of climate change.

White House Press Secretary Sean Spicer said on Friday he had not had the opportunity to talk to Trump about his views. White House councilor Kellyanne Conway also told Stephanopoulos on Friday he should ask Trump himself about his views.

Interior Secretary Ryan Zinke, who is charged with executing Trump's effort to expand drilling on federal land, told CNN he does not believe climate change is a hoax, but could not speak for the president.

US Ambassador to the UN Nikki Haley bucked the trend, saying Trump does believe that human activity plays some part in climate change during an interview on CNN's "State of the Union" that aired on Sunday.

"President Trump believes the climate is changing and he believes pollutants are part of the equation," she said.

Trump appears unwilling to put himself in jeopardy with his base, because most conservatives either agree with his past climate change denial, or are not invested in the issue enough to object, said David Konisky, associate professor at Indiana University's School of Public and Environmental Affairs.

"I do think the refusal to acknowledge climate change as a serious problem facing the United States and the world, as well as the reckless decision to pull out of the Paris Agreement, does risk alienating moderate Republicans and Independents," Konisky told CNBC in an email.

However, denying the importance of tackling climate change — and even its existence — will remain politically viable until more Americans demand climate action, and punish politicians who refuse to act, Konisky said.