Several U.S. lawmakers have accused Iran of being a major driver of instability in the Middle East.
The lawmakers were speaking at a July 16 hearing at the House Committee of Foreign Affairs that looked at Iran's "destabilizing" role in the region.
House Committee Republican Chairman Ed Royce accused Iran of arming the Palestinian group Hamas.
"Thanks to Iran, Hamas has rearmed since 2012. Iran is the one that rearmed them. And nearly 80 percent of Israel's citizens are fleeing to bomb shelters this week as a result," Royce said.
The panel's top Democratic member, Eliot Engel, also warned against Iran's regional influence.
Engel said that even if a comprehensive nuclear deal was reached with Iran that would enjoy broad support on Capitol Hill, Congress would not lift all sanctions on Iran unless "it ceased to be a bad actor in the region."
Based on reporting by Golnaz Esfandiari in Washington