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.

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

Sen. Josh Hawley (R-Mo.) is asking the Senate Homeland Security Committee to call on Homeland Security Secretary Alejandro Mayorkas and FBI director Christopher Wray to testify after the New