Senate Majority Leader Mitch McConnell (R-KY) said he would not spend federal funds investigating what President Trump says is “massive voter fraud in the 2016 presidential election.”

McConnell told CNN’s Jake Tapper that, although there are instances of voter fraud, he believes that it’s not “as widespread as Trump claims” and that combating voter fraud should be an issue “best left to the states” instead of the federal government.

“Election fraud does occur,” he told CNN’s State of the Union, adding that “there’s no evidence that occurred in such a significant number that it would have changed the presidential election.”

“I don’t think we ought to spend any federal money investigating that. I think the states can take a look at this issue. Many of them have tried to tighten their voter rolls, tried to purge people who are dead,” McConnell said.

Trump says he lost the popular vote by three to five million votes because of illegal immigrants in a meeting with congressional leaders at the White House, the Hill reported.

On Jan. 25, Trump called for a “major investigation” into the alleged voter fraud that would crack down on people registered in multiple states and deceased citizens still on voter rolls.

He reportedly considered signing an executive order on the subject, but “the administration has not taken any public action on the issue in roughly the past 10 days.”

Despite McConnell’s reluctance to investigate the issue at the federal level, Trump is still standing by his claim that illegal immigrants cost him the popular vote.

“Many people have come out and said I am right,” Trump said in an interview with Fox News’s Bill O’Reilly.