Editor’s Note: This report has been updated to reflect additional scenarios in the event of a contested election.

President Trump went on a tear against mail-in ballots Friday and claimed House Speaker Nancy Pelosi could become president if the presidential election is contested.

During remarks at the 2020 Council for National Policy meeting on Friday, the president predicted that it would take “weeks” if not months to determine the outcome of the presidential election, should the majority of voters cast their ballots by mail.

TRUMP SLAMS DEMOCRATS, SAYS WHERE THEY SEE 'DARKNESS,' HE SEES 'AMERICAN GREATNESS'

“I don’t think you’re going to know anything. I don’t think you’ll know for two weeks, I don’t think you’ll know four weeks later,” Trump said.

“You know, there’s a theory crazy Nancy Pelosi would become president,” Trump said. “I don’t know if its a theory or if that’s a fact, but I said that’s not good.”

He added: “There is a theory that if you don't have a choice, that the speaker of the House becomes president. … Add that to everything else.”

The “theory” the president was referring to is questionable, though the 20th Amendment allows Congress to decide by law who can act as president and how that person can be chosen in the interim, in the event a presidential ticket is not chosen. By statute, the speaker of the House is designated to act in this capacity.

However, if control of the House were also in question as a result of the election, it would be unclear what party was in the majority, and therefore unclear who in which party could be elected speaker of the House. Further, the process of certifying the results of the Electoral College is another X-factor. It determines who takes the oath of office. If the votes are contested and lawmakers cannot resolve the outcome, the House could hold a “contingent election” to determine the president which has only occurred twice in U.S. history — after the elections in 1800 and 1824.

In both cases, the contingent election resulted in one of the original presidential candidates – not anyone else in the line of succession – winning. So someone other than Pelosi could well be selected in that process.

Meanwhile, the president, on Friday, continued to rail against mail-in ballots, as he and the Republicans have done for months, warning of widespread fraud, and calling the process “filthy and dirty.”

“We voted in World War I, we voted in World War II, and now we can’t vote anymore?” Trump said, calling the chaos that he predicts would ensue over universal mail-in ballots a “tremendous embarrassment for our country.”

“This is a very serious problem for our great democracy. This is a very, very serious problem and something has to be done about it,” Trump said.

The president went on to warn about “double voting,” saying people will “send in a ballot, and then they’ll go vote,” and questioned whether states would have the capacity to be able to safeguard the process.

“This will be the greatest catastrophe, one of the greatest catastrophes in the history of our country,” he said.

Democrats, including Democratic presidential nominee Joe Biden, have accused the president of trying to “steal” or influence the election by blocking mail-in ballots.

“They think I am trying to steal the election. Just the opposite,” Trump said. “I want the fair results of the election.”

Meanwhile, a senior Trump campaign official doubled-down on the president’s remarks Friday afternoon, telling Fox News that Democrats are trying to “find a way to cast blame” before the “mayhem” at the ballots happen.

“The post office was never the issue,” the official told Fox News. “The Democrats know that universal mail-in ballots will cause mayhem at local elections and precincts who won’t be able to handle the volume of incoming ballots.”

The official added that they know “chaos will be inevitable”

“They know out is going to be an incredible headache and will have delayed results and they’re trying to find a way to cast blame before it happens,” the official said.

TRUMP: 'IF YOU CAN PROTEST IN PERSON, YOU CAN VOTE IN PERSON'

Meanwhile, Trump campaign communications director Tim Murtaugh said: “Democrats and the media claim that voter fraud doesn’t exist. Are they unaware of what happened in Paterson, N.J.? Or do they want to ignore it?”

Murtaugh was referring to a race in Paterson, N.J., where a judge this week ruled that a new election will be held in November for a disputed Paterson City Council seat, just weeks after the race's apparent winner and a sitting councilman were charged with voter fraud.

In that race, nearly 20 percent of mail-in ballots were disqualified.

“That’s a real world example of a universal mail-in voting scheme,” the campaign official told Fox News.

Republicans, for months, have been warning about possible fraud connected to mail-in voting. The Republican National Committee and the Trump campaign have filed lawsuit to hit back against efforts by Democrats to overhaul voting laws in response to the pandemic; this, while Democrats say that cases of actual voter fraud are limited and claim that Republicans are trying to suppress voter turnout to improve their chances of winning in November.

Biden’s campaign has said casting ballots by mail is the “most secure form of voting” amid the coronavirus pandemic.

Meanwhile, National Institute of Allergy and Infectious Diseases' Dr. Anthony Fauci said there is “no reason” Americans can’t vote in person for the 2020 presidential election, so long as voters follow proper social distancing guidelines amid the coronavirus pandemic.

“I think if carefully done, according to the guidelines, there’s no reason that I can see why that cannot be the case,” Fauci told ABC News this week. “If you go and wear a mask, if you observe the physical distancing, and don’t have a crowded situation, there’s no reason why [people] shouldn’t be able to do that.”

Fauci added that individuals who are “compromised physically or otherwise” and who are not interested in physically going to the polls on Election Day, can use mail-in voting.

But Fauci doubled down, saying, “There’s no reason why we shouldn’t be able to vote in person or otherwise.”

Fox News' Chad Pergram contributed to this report.