(MSNBC) — Donald Trump on the day New Hampshire voters head to the polls in the primary election estimated for the first time that his infamous wall on the southern border would cost $8 billion — and insisted yet again that Mexico will pay for it.

Asked how Trump came up with that number by MSNBC host Tamron Hall, the GOP front-runner explained that it is a “very simple calculation.”

“What we’re doing is we have 2,000 miles, right? 2,000 miles. It’s long but not 13,000 miles like they have in China,” he said, comparing his self-declared great wall with the Great Wall of China, which took hundreds of years to build and reportedly resulted in the death of hundreds of thousands of workers. “Of the 2,000, we don’t need 2,000, we need 1,000 because we have natural barriers … and I’m taking it price per square foot and a price per square, you know, per mile,” he said.

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