The White House coronavirus task force had its biggest fight yet on Saturday, pitting economic adviser Peter Navarro against infectious disease expert Anthony Fauci. At issue: How enthusiastically should the White House tout the prospects of an antimalarial drug to fight COVID-19?

Behind the scenes: This drama erupted into an epic Situation Room showdown. Trump's coronavirus task force gathered in the White House Situation Room on Saturday at about 1:30pm, according to four sources familiar with the conversation. Vice President Mike Pence sat at the head of the table.

Numerous government officials were at the table, including Fauci, coronavirus response coordinator Deborah Birx, Jared Kushner, acting Homeland Security Secretary Chad Wolf, and Commissioner of Food and Drugs Stephen Hahn.

Behind them sat staff, including Peter Navarro, tapped by Trump to compel private companies to meet the government's coronavirus needs under the Defense Production Act.

Toward the end of the meeting, Hahn began a discussion of the malaria drug hydroxychloroquine, which Trump believes could be a "game-changer" against the coronavirus.

Hahn gave an update about the drug and what he was seeing in different trials and real-world results.

Then Navarro got up. He brought over a stack of folders and dropped them on the table. People started passing them around.

"And the first words out of his mouth are that the studies that he's seen, I believe they're mostly overseas, show 'clear therapeutic efficacy,'" said a source familiar with the conversation. "Those are the exact words out of his mouth."

Navarro's comments set off a heated exchange about how the Trump administration and the president ought to talk about the malaria drug, which Fauci and other public health officials stress is unproven to combat COVID-19.

Fauci pushed back against Navarro, saying that there was only anecdotal evidence that hydroxychloroquine works against the coronavirus.

Researchers have said studies out of France and China are inadequate because they did not include control groups.

Fauci and others have said much more data is needed to prove that hydroxychloroquine is effective against the coronavirus.

As part of his role, Navarro has been trying to source hydroxychloroquine from around the world. He's also been trying to ensure that there are enough domestic production capabilities inside the U.S.

Fauci's mention of anecdotal evidence "just set Peter off," said one of the sources. Navarro pointed to the pile of folders on the desk, which included printouts of studies on hydroxychloroquine from around the world.

Navarro said to Fauci, "That's science, not anecdote," said another of the sources.

Navarro started raising his voice, and at one point accused Fauci of objecting to Trump's travel restrictions, saying, "You were the one who early on objected to the travel restrictions with China," saying that travel restrictions don't work. (Navarro was one of the earliest to push the China travel ban.)

Fauci looked confused, according to a source in the room. After Trump imposed the travel restrictions, Fauci has publicly praised the president's restriction on travel from China.

Pence was trying to moderate the heated discussion. "It was pretty clear that everyone was just trying to get Peter to sit down and stop being so confrontational," said one of the sources.

Eventually, Kushner turned to Navarro and said, "Peter, take yes for an answer," because most everyone agreed, by that time, it was important to surge the supply of the drug to hot zones.

The principals agreed that the administration's public stance should be that the decision to use the drug is between doctors and patients.

Trump ended up announcing at his press conference that he had 29 million doses of hydroxychloroquine in the Strategic National Stockpile.

Between the lines: "There has never been a confrontation in the task force meetings like the one yesterday," said a source familiar with the argument. "People speak up and there's robust debate, but there's never been a confrontation. Yesterday was the first confrontation."

In response to a request for comment on Axios' reporting, Katie Miller, a spokesperson for the vice president, said: "We don't comment on meetings in the Situation Room."

The bottom line: The way to discuss the drug's potential has become a fraught issue within the Trump administration.

Most members of the task force support a cautious approach to discussing the drug until it's proven.

Navarro, on the other hand, is convinced based on his reading that the drug works against the coronavirus and speaks about it enthusiastically.

Some of Trump's favorite TV hosts, including Fox's Sean Hannity, and friends including Rudy Giuliani, have also been touting the malaria drug for the coronavirus. Trump has made no secret who he sides with.

"What do you have to lose? Take it," the president said in a White House briefing on Saturday. "I really think they should take it. But it's their choice. And it's their doctor's choice or the doctors in the hospital. But hydroxychloroquine. Try it, if you'd like."

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