Two Republican US senators defended themselves on Friday against heavy criticism, including calls that they resign, for selling large amounts of stock before the coronavirus-induced market meltdown and after closed-door briefings on the outbreak.

Senate Intelligence Committee Chairman Richard Burr sold up to $1.7 million worth of stock on Feb 13 in 33 separate transactions after offering public assurances the government was ready to battle the virus. His financial filings were first reported by ProPublica.

Burr receives regular classified briefings on threats to the United States. Burr said he relied only on public news reports to guide his decision on the Feb. 13 stock sales.

Senator Kelly Loeffler also sold $3.1 million in shares in the weeks after lawmakers were first briefed on the virus, according to public filings. A report said the sales began after she participated in a private coronavirus briefing for senators.

Media reports about Burr and Loeffler, who have denied wrongdoing, prompted calls they leave office and other criticism from people as disparate as a progressive Democratic lawmaker and a conservative commentator.

Trump said the senators should "possibly" be investigated.