However, it is unclear to what extent the new rules will be implemented, as the Supreme Court decision appears to leave room for new court cases that could slow the decree.
In some states, ballots for mail-in voting will begin to be sent out in just a few weeks.
The president has long called for stricter rules around mail-in voting, after spreading the false claim that his 2020 election loss was due to widespread voter fraud.
According to Trump's decree, the Department of Homeland Security will develop a list of eligible voters. The post office will then only deliver ballots to these people.
