Appearing in a conservative radio show, Donald Trump’s national campaign manager, Corey Lewandowski, said that under a Trump presidency, undocumented immigrants would be rounded up and deported.

Lewandowski appeared on July 28 on the John Fredericks Show, a conservative radio program where he further clarified the Trump campaign’s stance on immigration reform.

When John Fredericks asked: “You guys are going to be committed to basically rounding anyone who is here illegally, rounding them up, and sending them back?”

Lewandowski agreed, saying the American people were tired of politicians who do not follow through with their pledges.

“They want someone who is a straight talker, who has a proven record of success, particularly in creating jobs, particularly when it comes to negotiations and doing what is best,” he said, adding that someone who has the interest of the country should be president.

Fredericks continued asking about Trump’s plan for the “11 to 30 million” undocumented immigrants in the country, citing an incorrect figure Trump has previously stated, according to Right Wing Watch.

“We’ve got a huge problem in this country, as we know the first step of solving our illegal alien problem,” Lewandowski explained. “This people are coming across our borders, they’re killing American citizens and many times have been deported in numerous occasions. They’re felons, as you’ve seen in California and other places.”

The Trump campaign’s solution: build an “impenetrable” wall. He then argued in favor of “self-deportation,” a policy advocated by the ill-fated Romney campaign of 2012.

“It is no surprise Trump is now adopting "self-deportation" recycling failed immigration policies that resulted in Republicans losing the 2012 election,” DREAM Action Coalition said to Latin Post. “What is most unfortunate, however, is that Trump is dragging the entire party further to the right and not even common sense Republicans [want] to stop the Trump bandwagon.”

Trump himself has spoken out against “self-deportation” back in 2012, blaming it, in part, for Romney’s loss, according to CNN.

"He had a crazy policy of self-deportation, which was maniacal," Trump told Newsmax at the time. "It sounded as bad as it was, and he lost all of the Latino vote."

Deporting 11 million people would affect their families as well as cost billions to the American taxpayer. A report from the Center for American Progress in February of 2015 explained that just deporting the estimated 5 million immigrants benefiting from the president’s executive actions would cost $50 billion.

Lewandowski also did not explain how to pay for the “impenetrable” wall.

Listen to the full interview: