Former President Donald Trump blasted VP Kamala Harris on immigration in a Fox News Town Hall making the case that "she was in charge of the border" as illegal immigration surged to record levels in recent years.

"They want open borders," Trump told Fox News’ Sean Hannity in a town hall event on Wednesday night.  "She wants open borders. Now she's all of a sudden said, oh, I think we're closing the borders. She was the border czar, whether you like it or not, but even if you don't want to use that term. She was in charge of the border."

"It's the worst border in the history of the world, not just here. There's never been a country that allowed 21 million people to come in over a three-year period. There's never been. And 21 million people, many of whom are from prisons, many of whom are murderers and drug dealers and child traffickers."

Trump continued, "And, by the way, women traffickers, you know, women trafficking is the biggest, and they're traffickers in women. And they're coming in now and they're putting them in our Social Security accounts, and they're putting them in Medicare. And just one thing, if you take a look, take a look. Over the last week, I said this was going to happen. And it's happening because these people are tougher than our criminals are, our criminals are nice people by comparison."

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Former President Trump and Vice President Harris side by side split image.  (Getty Images)

Trump said that "more terrorists have come into the United States in the last three years,"

"And I think probably 50 years. There's never been anything like it. These people are so bad. They're so dangerous. What they've done to our country is they're destroying our country, and we can't let this happen."

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Flanked by labor union leaders, Democratic presidential candidate Vice President Kamala Harris speaks to union workers during a campaign event on September 02, 2024 at Northwestern High School in Detroit, Michigan. (Scott Olson/Getty Images)

Trump explained that "most people don't know that you have that many countries" that are "emptying out their prisons and jails" into the United States.

"They're emptying out their mental institutions and insane asylums. They're emptying out the sickest people, and they're emptying all into the United States."

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Former US President and Republican presidential candidate Donald Trump arrives to speak about national security during a campaign rally at the North Carolina Aviation Museum & Hall of Fame in Asheboro, North Carolina, August 21, 2024.  (PETER ZAY/AFP via Getty Images)

Immigration is the second most important issue to voters, behind the economy, heading into the 2024 election, according to recent Fox News polling.

Polling also shows that Trump leads Harris on the immigration issue where he beats Harris by 14 points in a Fox News Poll, 16 points in Marist’s poll, 18 points in Marquette University’s poll, and 13 points in the Wall Street Journal’s poll; all conducted after Biden stood down from re-election.

Fox News Digital's Remy Numa contributed to this report