Acting Attorney General Todd Blanche said the Trump administration's efforts to revoke the citizenship of immigrants who obtained it through fraud "should be worried." 

Blanche told CBS News on Wednesday the administration is pursuing more denaturalization cases than have been done in the last nine years. 

Blanche said the crackdown is broad and not limited to "anybody in particular," but he declined to provide any numbers. 

"I think you're going to hear more about this in the coming days and weeks. There are a lot of individuals who are citizens who shouldn't be," Blanche said. 

While the Department of Homeland Security oversees most aspects of the U.S. immigration system, the Justice Department is tasked with revoking citizenship of naturalized citizens. Last year, the Justice Department directed officials to prioritize a broad category of people for denaturalization, including those accused of financial fraud.