Sens. John McCain, R-Ariz., and Joe Lieberman, I-Conn., met with Israeli Prime Minister Benjamin Netanyahu Friday, saying they "continue to stand with Israel at a time of historic change in the region."
The lawmakers were in Jerusalem as part of their Middle East tour. They also visited Tunisia, Morocco, Lebanon, and Jordan.
The volatile situation in Egypt, Libya, and other countries in the region has caused great concern in the international community.
"I think we should be concerned about the Muslim Brotherhood because of their past connections with terrorist organizations and their past positions they've taken on various issues," Sen. McCain said.
"I understand there are 'splits' within the Muslim Brotherhood. I'm still worried," he added.
Many analysts fear the Muslim Brotherhood could take over Egypt through democratic elections and turn the country into a radical Islamic regime.