President Trump on Friday said he was being sarcastic when he suggested multiple times a day earlier that scientists should consider exposing the body to light, heat and disinfectants as a potential treatment for the coronavirus.

"I was asking a question sarcastically to reporters like you just to see what would happen," Trump told reporters at an Oval Office bill signing.

"I was asking a sarcastic - and a very sarcastic question - to the reporters in the room about disinfectant on the inside," the president continued. "But it does kill it, and it would kill it on the hands and that would make things much better. That was done in the form of a sarcastic question to the reporters."

When a journalist in the Oval Office pointed out that Trump had turned to experts next to the stage when he first raised the idea on Thursday, the president claimed he was asking those officials "whether or not sun and disinfectant on the hands ... can help us."

The president's explanation drew skepticism among those who watched the briefing, where Trump directly turned to other government officials to ask about the idea.

"It didn't seem like it was coming off as sarcastic when he was talking and turning to Dr. Birx on the side," Fox News anchor Bret Baier said on air after Trump's walk-back was reported.

Trump on Thursday latched on to a presentation from a Department of Homeland Security official who detailed initial findings that the coronavirus deteriorates more quickly when subjected to higher levels of heat, humidity and ultraviolet rays from the sun.

"So, supposing we hit the body with a tremendous - whether it's ultraviolet or just very powerful light - and I think you said that hasn't been checked but you're going to test it," Trump said. "And then I said, supposing you brought the light inside of the body, which you can do either through the skin or in some other way. And I think you said you're going to test that too. Sounds interesting."

Trump also asked if there was a way to use disinfectants on the body "by injection inside or almost a cleaning."

Asked later if it was irresponsible to give Americans the impression that going outside amid the pandemic would be safe based on the findings, Trump turned to Deborah Birx, a physician coordinating the White House response to the pandemic, and inquired about using the light and heat as a treatment.

"Deborah, have you ever heard of that? The heat and the light, relative to certain viruses, yes, but relative to this virus?"

"Not as a treatment," Birx replied. "I mean, certainly ... when you have a fever, it helps your body respond. But not as - I've not seen heat or light."

"I think it's a great thing to look at," Trump said.

The president's remarks were widely and quickly panned by medical experts, elected officials and private companies who warned Americans not to ingest chemicals.

Former Food and Drug Administration head Scott Gottlieb said there's "no circumstance" in which an individual should inject themselves with a disinfectant.

The company that makes Lysol also warned on Friday against ingesting its products.

The White House sought to pin the backlash on the media, issuing a statement that accused the press of taking Trump's remarks out of context.

"President Trump has repeatedly said that Americans should consult with medical doctors regarding coronavirus treatment, a point that he emphasized again during yesterday's briefing," press secretary Kayleigh McEnany said.