WASHINGTON, D.C. — North Carolina Sen. Richard Burr is facing calls to resign, following reports that he sold up to $1.7 million worth of stocks ahead of the market’s downward turn in light of the coronavirus.

In a statement Friday, Burr pushed back against questions as to whether he relied on information provided to members of Congress in private briefings when he made the stock decisions, saying "public news reports" guided his choices.

He also announced that he had asked the Senate’s ethics panel to review the matter. "It is my belief that an independent review is warranted to ensure full and complete transparency," he wrote in a letter to the committee.

The criticism of Burr, a Republican, came from across the political spectrum.

In a tweet, Rep. Alexandria Ocasio-Cortez, a Democrat from New York, wrote “he needs to resign.”

Thom Tillis, North Carolina’s other senator and a fellow Republican, did not call for Burr to step down but did tweet, “Given the circumstances, Senator Burr owes North Carolinians an explanation.”

Fox News host Tucker Carlson weighed in on his show Thursday night, rebuking Burr.

“Maybe there’s an honest explanation for what he did. If there is, he should share it with the rest of us immediately,” Carlson said. “Otherwise, he must resign from the Senate and face prosecution for insider trading.”

ProPublica and the Center for Responsive Politics first reported on Burr’s stock sales Thursday.

Burr dumped between roughly $600,000 and $1.7 million in stocks in mid-February, before the current Wall Street meltdown, according to financial disclosure forms.

The sale came in the weeks after a Senate-wide closed door briefing on the coronavirus. According to a Feb. 27 report by Reuters, the Senate Intelligence Committee, of which Burr is the chairman, was also receiving daily updates on the virus.

In a statement Friday, Burr pushed back against notions that nonpublic information guided his investment choices.

“I relied solely on public news reports to guide my decision regarding the sale of stocks on February 13. Specifically, I closely followed CNBC’s daily health and science reporting out of its Asia bureaus at the time,” he wrote.

Could this case qualify as insider trading?

James Cox, a securities law expert at Duke University, said there are a few critical questions in any insider trading investigation. "The issue is: what did you know and when did you know it?" he said. "Then what follows from that is: when did you trade and how much did you trade?"

Asked about Burr's stock sales, Cox said, “I think it's a very strong case for opening an investigation, which the [U.S. Securities and Exchange Commission] does not do lightly."

The SEC website says all of the agency's investigations are conducted privately.

A handful of other senators also made stock trades ahead of the market’s collapse. Asked if they should be investigated, President Donald Trump said Friday that he didn’t know, calling the senators “honorable" people.

In 2012, then-President Barack Obama signed the STOCK Act. The law in essence banned insider trading by members of Congress.

Burr was one of three senators to vote against the bill in the upper chamber, arguing insider trading was already barred by other laws.

Earlier on Thursday, NPR published a recording of Burr speaking at a private event in late February, where he gave dire warnings about the coronavirus, saying it is "probably more akin to the 1918 pandemic."

NPR reports those remarks were far more stark than Burr’s public comments about the virus.

A Burr spokesperson responded to that report, saying, “Since early February, whether in constituent meetings or open hearings, he has worked to educate the public about the tools and resources our government has to confront the spread of coronavirus. At the same time, he has urged public officials to fully utilize every tool at their disposal in this effort.”

Burr sponsored the Pandemic and All-Hazards Preparedness Act, first enacted in 2006, which sets up the framework for how the federal government responds to such a threat.

In a Fox News op-ed published on Feb. 7 - about a week before the stock sale, according to the filings - Burr joined with Tennessee Republican Sen. Lamar Alexander in writing that while Americans are "rightfully concerned" about COVID-19, "the United States today is better prepared than ever before to face emerging public health threats, like the coronavirus."