White House Press Secretary Sean Spicer dug in Tuesday on President Trump’s claim to congressional leaders that he lost the popular vote to Hillary Clinton last November because between 3 million and 5 million "illegals" cast ballots – even as House Speaker Paul Ryan pushed back.

“I’ve seen no evidence to that effect. I’ve made that very, very clear,” Ryan said earlier Tuesday.

But Spicer, asked repeatedly by reporters about the issue at Tuesday’s briefing, said Trump believes this to be the case.

“It was a comment he made on a longstanding belief,” Spicer said. “… He believes what he believes based on the information he’s been provided.”

Spicer said Trump remains “comfortable” with his Electoral College victory, which handed him the presidency regardless of the popular vote totals.

Pressed on whether the administration would pursue an investigation into illegal immigrants voting given Trump’s beliefs, Spicer said: “Maybe we will.” He later backed off the suggestion, saying only that anything is possible.

Trump made the claim during a meeting with congressional leaders Monday, though he’s made similar assertions before.

In late November, Trump tweeted that he had "won the popular vote if you deduct the millions of people who voted illegally."

At the time, multiple law enforcement sources told Fox News that there was no evidence to support Trump's claims.

Trump defeated Clinton in the Electoral College, collecting 304 votes to her 227. However, Clinton won the popular vote by more than 2.8 million ballots.

Spicer said Tuesday that Trump’s claim was based on “studies and evidence.”

Spicer did not provide hard data to back up the claim, citing only a 2008 study that called for updating voter rolls but did not conclude there has been pervasive election fraud.

Senate Minority Leader Chuck Schumer, D-N.Y., on Tuesday blasted Trump over the comments, which he described as falsehoods, and said the administration ought to talk about jobs.

Spicer, though, said their focus right now is getting Americans back to work – something Trump has addressed in a flurry of executive actions including measures Tuesday aimed at reviving stalled pipeline projects.

The Associated Press contributed to this report.