Updated

Defense Secretary Jim Mattis says Congress should approve a formal authorization for U.S. military forces to fight the Islamic State in Syria.

Mattis calls the Islamic State a "clear and present danger" and says he wonders why Congress hasn't acted already. He says an authorization from Congress to fight the extremist group would show resolve.

He was testifying Wednesday before the Senate Appropriations defense subcommittee.

Congress in 2001 gave President George W. Bush approval to attack any countries or groups involved in the Sept. 11 attacks. The Trump administration, as did the Obama administration, relies on that nearly 16-year-old authority to send U.S. troops into combat against the Islamic State.

This is Mattis' first appearance before a congressional committee since being confirmed in January as President Donald Trump's defense chief.