President Trump on Thursday suggested delaying the 2020 election “until people can properly, securely and safely vote.”

In a series of tweets, the president attacked mail-in voting, saying it “is already proving to be a catastrophic disaster” and would cause “the most INACCURATE & FRAUDULENT Election in history.”

“The Dems talk of foreign influence in voting, but they know that Mail-In Voting is an easy way for foreign countries to enter the race,” he added.

Federal law requires federal elections to be held the Tuesday after the first Monday in November. A change in the law would require an act of Congress.

In a statement responding to the tweets Thursday, Hogan Gidley, Trump 2020 national press secretary, said the president is “just raising a question about the chaos Democrats have created with their insistence on all mail-in voting.”

“They are using coronavirus as their means to try to institute universal mail-in voting, which means sending every registered voter a ballot whether they asked for one or not. Voter rolls are notoriously full of bad addresses for people who have moved, are non-citizens, or are even deceased,” he said.

Gidley added that universal mail-in voting “invites chaos and severe delays in results,” citing the New York Congressional primary, which still has not finished tallying results more than a month after the election.

In May, Twitter fact-checked a tweet by the president saying,”There is NO WAY (ZERO!) that Mail-In Ballots will be anything less than substantially fraudulent. Mail boxes will be robbed, ballots will be forged & even illegally printed out & fraudulently signed.”

Twitter added a link to each tweet in his May thread giving users the option to “get the facts about mail-in ballots.”

“These claims are unsubstantiated, according to CNN, Washington Post and others. Experts say mail-in ballots are very rarely linked to voter fraud,” Twitter wrote.

While the president has repeatedly taken aim at mail-in voting, 29 states already have no-excuse absentee voting, including the states where control of the White House and the Senate will be decided: Wisconsin, Michigan, Pennsylvania, Florida, Arizona, North Carolina, Georgia, Iowa, Montana, and Maine.

A study by the National Vote At Home Coalition found that out of 100 million votes cast in Oregon since mail-in voting was adopted in 2000, there were only twelve cases of fraud.

States take a number of steps to prevent fraud, including signature matching, requiring identifying information such as the last four digits of the Social Security number and using barcodes for each ballot.