Markwayne Mullin, the US homeland security secretary, doubled down on Donald Trump's unsubstantiated election claims on Friday amid his agency's efforts to support the president's agenda.
Trump used a review compiled by the Department of Homeland Security (DHS) as the basis of many of his unsubstantiated claims on Thursday during his televised primetime address to the nation.
"This isn't about rehashing the 2020 election. This is just exposing what took place, and to make sure it never happens again," Mullin said, after the president's speech was widely criticized for revealing no new information about the safety and security of the US elections, despite claiming that system falls "catastrophically short" of "greatness".
Mullin claimed that the DHS identified "250,000 noncitizens registered to vote in California, Pennsylvania, New Jersey and Nevada". However, election experts, including David Becker, the executive director of the nonpartisan Center for Election Innovation & Research, said the administration has not been "transparent about the methodology" in reaching that number.
Related: Five claims Trump made in primetime address not backed up by evidence