One of Donald Trump’s fiercest defenders urged the president on Thursday to pay attention to scientific facts instead of spit-balling a coronavirus death rate and insisting that up to “hundreds of thousands” of Americans could catch the virus with little ill effect and still go to work.

“I don’t know what he was talking about,” Sen. Lindsey Graham (R-S.C.) told reporters after Trump explained to Sean Hannity on Fox News that he had a “hunch” the death rate for COVID-19, the disease caused by the virus, is less than 1%. The World Health Organization has reported that the death rate is 3.4%.

“I would encourage the president, if he’s going to report things, to make sure that the science is behind what he says,” Graham added, noting: “I listen to the scientists when it comes to the numbers.”

Lindsey Graham to @mkraju on Trump citing "hunch" to contradict WHO's 3.4% death rate for coronavirus: "I listen to the scientists when it comes to the numbers, and I would encourage the president if he's going to report things to make sure the science is behind what he's saying" pic.twitter.com/dSsCFdjSHG — Aaron Rupar (@atrupar) March 5, 2020

Trump took health experts by surprise when he cooked up his own death rate during an interview with Hannity on Wednesday — and estimated that as many as “hundreds of thousands” of people with the illness could “get better just by, you know, sitting around and even going to work.”

Health experts have warned anyone with possible COVID-19 symptoms not to go to work to avoid further spreading the highly contagious disease.

Trump has also repeatedly promised that a vaccine for the illness is mere months away — even though experts have repeatedly corrected him that it will take at least a year to 18 months to have a usable vaccine.

Last week, Trump boasted at a press conference that ﻿COVID-19 cases in the U.S. would “within a couple of days ... be down to close to zero.” He added: “That’s a pretty good job we’ve done.”

As of Thursday evening, the U.S. had at least 210 cases and 12 deaths.