The comments came as the president discussed the coronavirus stimulus bill passed by the House of Representatives, and signed on Friday, providing a $2tn (£1.7tn) stimulus to Americans.
Democrats had attempted to include $4bn worth of measures to safeguard November’s presidential election, with specific provisions for mail and absentee ballots as well as online and same-day voter registration, and expanding early voting by 15 days.
“The things they had in there were crazy. They had things, levels of voting that if you’d ever agreed to it, you’d never have a Republican elected in this country again,” said Mr Trump during an interview on Fox & Friends.
“They had things in there about election days and what you do and all sorts of clawbacks. They had things that were just totally crazy and had nothing to do with workers that lost their jobs and companies that we have to save.”
The House passed the bill with watered down provisions for states to make preparations for the election during the coronavirus pandemic, totalling $400 million in funding without specific requirements for how the money should be used.
Zoe Logfren, the committee chairwoman who led the campaign to include additional election funds and policies in the House of Representatives version of the package, said the president was “morally bankrupt”
She added: “He is apparently willing to expose voters to the deadly COVID-19 for purely partisan political advantage.”
Democrats said that president Trump’s comments showed that suppressing the vote was part of his re-election strategy for 2020.
In a statement, Democratic National Committee (DNC) spokeswoman Xochitl Hinojosa said: “Ensuring that Americans can vote during the Covid-19 crisis is fundamental to maintaining our democracy. It is shocking that Trump is essentially admitting that when the American people vote, Republican lose,”
She added: “Trump knows that suppressing the vote is the only way he and Republicans win in November.”
Republicans have traditionally said that Democratic reforms to the US election system would increase voter fraud, whilst Democrats have challenged Republicans for putting barriers in the way of minorities, young people, and other groups from voting.