President Trump continues to believe that millions of illegal ballots cost him the popular vote in the election, White House press secretary Sean Spicer said Tuesday.

"The president does believe that," Spicer said when asked about comments Trump reportedly made behind closed doors Monday, in which he lamented the number of illegal voters who participated in the election.

"He's stated that before," Spicer added.

The White House spokesman said Trump's beliefs about the votes are "based on studies and information he has."