 -- President Trump will sign an executive order today related to alleged voter fraud, White House press secretary Sean Spicer confirmed, telling reporters the directive will "follow up" on the "major" investigation announced by the president on Wednesday.

"It will be a follow-up on the announcement yesterday to better understand voter fraud," Spicer said.

The White House did not offer further details as to what agencies would be responsible for the investigation.

In an exclusive interview with ABC News, Trump insisted there is “a lot to look into” regarding alleged voter fraud.

“You have people that are registered who are dead, who are illegals, who are in two states. You have people registered in two states. They vote twice. There are millions of votes, in my opinion,” Trump told ABC's David Muir during an interview at the White House.

The president and members of his administration have repeatedly made unsubstantiated claims that millions of people illegally voted in the 2016 presidential election.