The Pentagon has expressed concerns over the increase in attacks on U.S. forces in Iraq and Syria. The Pentagon has confirmed a total of 55 attacks, injuring dozens of U.S. troops in the two countries. However, the Pentagon said U.S. forces thwarted most of the attacks using air defence systems. Last week, Iran-backed Houthi fighters downed an American drone. Militant groups in the Middle East are up in arms against the U.S. over its backing of Israel.