JERUSALEM (AP) — The American military chief is in Israel to observe the largest armed forces drill between the two countries.

Gen. Martin Dempsey, chairman of the U.S. Joint Chiefs of Staff, was meeting Sunday with Israeli Defense Minister Ehud Barak at the beginning of his visit. He'll also be meeting with his Israeli counterpart and the country's president.

He plans to oversee elements of Austere Challenge 2012, an air defense drill that includes more than 3,500 Americans and 1,000 Israelis. They are practicing their ability to work together against a range of threats facing Israel.

The joint exercise tests multiple Israeli and American air defense systems against incoming missiles and rockets from places as far away as Iran.