Federal officials have instructed border patrol agents not to deport illegal immigrants so they can remain in the country and vote in November, Donald Trump alleged during a roundtable Friday morning.

"They're letting people pour into this country so they can go and vote," said the Republican presidential nominee while meeting with members of the National Border Patrol Council inside Trump Tower.

His remark came during a conversation with Art Del Cueto, national vice president of NBPC, which represents more than 18,000 border patrol agents and personnel.

Del Cueto had reportedly told Trump that scores of border patrol agents had been advised not to deport criminal illegal immigrants and instead focus on "trying to get the people who are on the waiting list to hurry up and get them their immigration status corrected."

"Why?" Trump asked, to which Del Cueto responded: "So they can go ahead and vote before the election."

"Big statement, fellas," Trump told reporters who were present for the meeting. "You're not going to write it. That's huge. They're letting people pour into the country so they can go and vote.

"You hear a thing like that, and it's a disgrace," he added. He said the immigration system "will be a lot different if I get elected."'

Trump often describes the electoral process as "rigged," and began encouraging his supporters earlier this summer to closely monitor their local polling stations on Election Day to prevent fraudulent activity from taking place.

Last weekend, for example, he told voters in Manheim, Pa., "you've got to go out, and you've got to get your friends, and you've got to get everybody you know, and you got to watch the polling booths, because I hear too many stories about Pennsylvania, certain areas."

Trump has drawn criticism for suggesting the electoral process might be skewed in Clinton's favor.

"I don't think it's good for democracy to have a major candidate for president doubt the outcome," South Carolina Sen. Lindsey Graham told CNN on Thursday. "The system's not rigged against [Trump], as far as I can tell, and when you suggest it might be, then that's a message to your supporters and to the country as a whole that you can't trust the outcome of an American election."