WATCH: Mullin holds news conference on election security after Trump's address to the nation

Homeland Security Secretary Markwayne Mullin discussed election security at the White House complex. The Friday briefing follows President Donald Trump's primetime speech Thursday night, where he revived falsehoods about voter fraud ahead of the November midterms.

Watch in the video player above.

Trump used a primetime address to the nation to elevate his yearslong push to raise doubts about the legitimacy of U.S. elections and dispute his 2020 loss — this time, to justify his push to pass a strict voter ID bill. His allegations of interference and influence didn't include key context. Nor did he produce evidence that votes had been manipulated or that the election outcome had been altered.

DHS secretary pledges to aggressively chase voter fraud cases

Mullin said if anyone votes illegally in the upcoming midterm elections, "we will hunt you down, we will find you and we will prosecute you."

In a White House briefing doubling down on Trump's primetime election claims, Mullin also threatened fines, penalties or prison time for state election officials who refuse to hand over sensitive voter data to DHS.

READ MORE: Here's what makes American elections so complicated and secure

He said states that don't elect to use DHS's recently updated tool for identifying noncitizen voters, will become "a priority" for investigations.

The comments come as a federal judge has blocked the use of DHS's updated system, citing voter privacy and the fact that it can result in the wrongful purging of eligible voters.