George Stephanopoulos. ABC George Stephanopoulos grilled Vice President-elect Mike Pence on Sunday over President-elect Donald Trump's unsubstantiated claims that millions of people voted illegally.

In an interview on "This Week," the ABC anchor brought up Trump's baseless claim, asking Pence if it "was responsible for a president-elect to make false statements like that?"

Pence repeatedly attempted to support Trump by citing a Pew Research study which found that voter registration systems needed to be updated. But Stephanopoulos countered by saying the study's author said there's still no evidence of widespread voter fraud.

"What is historic here is that our president-elect won 30 to 50 states. He won more counties than any candidate on our side since Ronald Reagan," Pence said.

He added: "And the fact that some partisans, who are frustrated with the outcome of the election and disappointed with the outcome of the election, are pointing to the popular vote, I can assure you, if this had been about the popular vote, Donald Trump and I have been campaigning a whole lot more in Illinois and California and New York."

Stephanopoulos pushed back, saying he was "not questioning" Trump's victory but asking if Pence believes "it's [Trump's] right to make false statements."

"It's his right to express his opinion as president-elect of the United States," Pence said. "I think one of the things that's refreshing about our president-elect and one of the reasons why I think he made such an incredible connection with people all across this country is because he tells you what's on his mind."

"But why is it refreshing to make false statements?" Stephanopoulos asked.

"I don't know that that is a false statement, George, and neither do you," Pence said.

" I know there's no evidence for it," Stephanopoulos replied.

Pence wasn't the only top official from the incoming Trump administration pressed about the president-elect's voter fraud claims.

Appearing on "Face The Nation," incoming White House chief of staff Reince Priebus said "it's possible" millions of people voted illegally, adding that estimates of false votes are "all over the map."

Priebus characterized Trump's claims as evidence that the president-elect was "challenging conventional thought."

"I think he's done a great job. I think the president elect is someone who has pushed the envelope and caused people to think in this country, is not taking conventional thought on every single issue," Priebus said.

Watch Pence on 'This Week' below: