Nobody at the White House was able to say on Friday whether President Donald Trump believes in climate change.

It was a burning question the day after Trump announced that he had decided to withdraw the United States from the Paris climate accord.

Trump in recent years has expressed skepticism about whether climate change is real, sometimes calling it a hoax.

But since becoming president, he has not offered an opinion.

Reporters have asked several senior officials about Trump's view, but have not gotten an answer.

"I have not had an opportunity to have that discussion," White House spokesman Sean Spicer told reporters.

Environmental Protection Agency Administrator Scott Pruitt gave his own view on the subject, saying he believes human activity plays a role in global warming, but measuring that contribution with precision is difficult.

But speaking to reporters at the White House, Pruitt declined to directly answer questions about whether the president still believed global warming was "a hoax."

Pruitt, asked if he himself believed climate change is occurring, said he has indicated that "human activity contributes to it in some manner. Measuring with precision, from my perspective, the degree of human contribution is very challenging."

Trump counselor Kellyanne Conway was asked on ABC's "Good Morning America" show whether Trump believed in climate change. She said he believes in clean air and water and a clean environment.

Pressed, on Trump's view, she said: "You should ask him that. And I hope you have your chance."

Trump himself declined to answer when a reporter asked him to respond to criticism from Fox News commentator Geraldo Rivera, who said he was appalled by Trump's decision to withdraw.

- Reuters