A day after he floated the idea of using disinfectants and light to treat COVID-19, President Donald Trump declined to take any questions at his daily coronavirus briefing at the White House.

The briefing — which can sometimes last about two hours — was over in just over 20 minutes, following remarks from Trump, Vice President Mike Pence and FDA head Stephen Hahn. The two top government doctors charged with combating the coronavirus crisis, Anthony Fauci and Deborah Birx, were not in attendance.

On Thursday, Trump drew widespread criticism for suggesting light, heat and injecting disinfectants could be used to treat coronavirus patients.

“So, supposing we hit the body with a tremendous — whether it’s ultraviolet or just very powerful light — and I think you said that that hasn’t been checked, but you’re going to test it. And then I said, supposing you brought the light inside 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 said then, addressing a Homeland Security official who’d said tests show the virus dies on surfaces more quickly in the heat.

“And then I see the disinfectant, where it knocks it out in a minute. One minute. And is there a way we can do something like that, by injection inside or almost a cleaning? Because you see it gets in the lungs and it does a tremendous number on the lungs. So it would be interesting to check that. So, that, you’re going to have to use medical doctors with. But it sounds, it sounds interesting to me.”

Doctors called the idea dangerous and irresponsible, while state and local government agencies and disinfectant manufacturers warned the products should not be ingested or injected.

Trump tried walking back the comments earlier Friday, claiming his suggestions had been “sarcastic.”

“I was asking a question sarcastically to reporters just like you, just to see what would happen,” Trump said during a bill signing for the coronavirus aid package.

But asked some more about the comments, he again suggested light could be used to kill the virus in the body.

“I’d like them now to look as it pertains to the human body, not just sitting on a railing or sitting on a wall. I’d like them to look as it pertains — because maybe there’s something there. They have to work with the doc — I’m not a doctor. They have to work with the doctors. But maybe there is something to light and the human body and helping people that are dying,” Trump said.

Asked if he was encouraging people to ingest disinfectant, he said, “No, of course — no.”