Senate Judiciary Committee Chairman Lindsey Graham (R-SC) holds a news conference at the U.S. Capitol March 25, 2019 in Washington, DC.

Sen. Lindsey Graham said Thursday that "everybody" running for president in 2020 should publicly release their tax returns — including President Donald Trump.

The senior GOP senator from South Carolina weighed in just hours after House Ways and Means Committee Chairman Richard Neal, D-Mass., said he had formally submitted a request to the Treasury Department for six years of Trump's personal and business tax returns.

"I think you should release your tax returns if you're running for president in 2020," Graham told reporters.

"I think everybody should," Graham added. "That's just my view, it'd be good for the country."

A spokesman for the senator confirmed to CNBC that Graham believes Trump should release his tax returns.

Graham has established himself as one of Trump's closest allies on Capitol Hill. But his stance that presidential candidates ought to disclose their tax information puts some distance between him and the president, who has refused to release his returns before or after the 2016 election.

Neal's request to IRS Commissioner Charles Rettig is expected to trigger a protracted battle with the Trump administration, whose officials have also signaled their unwillingness to hand over the president's financial documents.

Treasury Secretary Steven Mnuchin said at a Ways and Means hearing last month that he would protect Trump "as we would protect any individual taxpayer under their rights" if the request for his returns was made.

White House press secretary Sarah Huckabee Sanders said in a Fox News interview Thursday that Trump "doesn't have any intention to release those returns," saying that the president's taxes "continue to be under audit."