In an interview on ABC's "This Week," Homeland Security Secretary Alejandro Mayorkas warned of a "very difficult threat landscape" after the New Orleans truck attack.

President Biden will visit New Orleans today after the horrific attack on Bourbon Street. This comes as new details emerge on the attacker. Former DHS Secretary Jeh Johnson joins Ana Cabrera to provide more insight on the security measures.

He said the Bourbon Street attack was part of "a significant increase in what we term homegrown violent extremism."