During an interview with Fox News host Sean Hannity, he was asked how long it would take him to “get things back to where you had it when you left”, if he was elected president again.
“Very quickly, except for one thing: millions of people are in our country now that shouldn’t be here. Many of them are prisoners, criminals,” the former president replied.
“Would you deport them?” Hannity asked. “The bad ones I would deport. Millions and millions of people have – they’re are poisoning our country. They’re poisoning – I’d like to be nice about it,” replied Mr Trump.
The one-time president also said Venezuela was “emptying their prisons” without providing evidence.
“Yesterday, I heard that Venezuela is emptying their prisons out into the United States. Now, I wasn’t that shocked because other countries have been doing it and I’ve been reading about it and seeing it,” he said.
“So, I’m almost surprised it took them so long, but Venezuela is emptying their prison population into the United States going right through the border like nothing,” he added.
“We’re poisoning our country, and it’s very hard to come back from that,” Mr Trump continued.
The remarks come as Republican Florida governor Ron DeSantis, seen as a possible rival of Mr Trump as he could announce plans for a presidential run for 2024, was sued for orchestrating the transport of nearly 50 mostly Venezuelan immigrants from Texas to Martha’s Vineyard.
Meanwhile, Mr Trump’s attorneys have been ordered to say whether they actually believed the FBI had planted incriminating evidence in the documents seized from Mar-a-Lago.
Mr Trump had claimed in the interview that as president, he had the authority to declassify top secret documents just “by thinking about it”.
He also blamed banks for failing to check his company’s valuations and bizarrely suggested the FBI seized his will and could also have been looking for Hillary Clinton’s emails in his mansion.
The interview on Fox News was broadcast amid more trouble for Mr Trump after New York’s attorney general sued the Trump Organization as well as his three adult children for inflating the worth of his properties by billions of dollars and habitually misleading banks.