Alex Brandon, File, Associated Press
FILE - In this July 27, 2010 file photo, Marine Corps Gen. James Mattis testifies on Capitol Hill in Washington. Mattis, commander of U.S. forces in the Middle East, is scheduled to speak Thursday Oct. 4, 2012, at the University of Wyoming.

LARAMIE, Wyo. — The top U.S. military commander in the Middle East says attacks on international forces by Afghan soldiers and police are disheartening.

But Gen. James Mattis says such treachery is a part of war and will not diminish the U.S. commitment to Afghanistan.

He says measures have been taken to help reduce the so-called insider attacks that have claimed more than 50 American lives this year.

Mattis spoke and answered questions for little over an hour Thursday at the University of Wyoming.

He is commander of U.S. military operations in the Middle East, which includes Afghanistan, Egypt, Iran, Iraq, Pakistan and Syria.

Mattis says Iran is his biggest worry every day in the region because of its involvement in Syria and elsewhere.