By Maya Gebeily and Tom Perry

BEIRUT, July 21 (Reuters) - Lebanese President Joseph Aoun will meet U.S. President Donald Trump at the White House on Tuesday to present a plan on how to disarm Iran-backed militant group Hezbollah and secure Israel's withdrawal from Lebanon.

Aoun, who served as the commander of Lebanon's U.S.-backed army before being elected president last year, is the first Lebanese head of state in nearly 20 years to visit the White House, where he will meet Trump face-to-face for the first time.