Watch CBSN Live

FBI director: ISIS may try to take more American hostages

FBI Director James Comey said in written testimony to Congress Wednesday that Americans within reach of the Islamic State of Iraq and Syria (ISIS, also known as ISIL) may be at risk of being kidnapped.

"We are deeply concerned about the safety and security of American citizens worldwide," Comey said in his written testimony ahead of a hearing in front of the House Homeland Security Committee. "ISIL and other foreign terrorist organizations may continue to try to capture American hostages in an attempt to force the U.S. government and people into making concessions that would only strengthen ISIL and further its terrorist operations."

Obama on those who killed James Foley: "America does not forget"

Over the summer, ISIS beheaded two kidnapped American journalists, James Foley and Steven Sotloff, after the U.S. began conducting airstrikes against the group to protect American assets in the region and help deliver humanitarian aid to a group of trapped religious minorities that ISIS was threatening to kill.

Some of ISIS' revenue comes from demanding ransoms in exchange for hostages they have kidnapped. European countries and companies based there frequently pay the ransom demands, but the U.S. has a policy not to pay ransoms.

In the case of Foley, ISIS attempted to extort more than $130 million in exchange for his release.

But experts say the U.S. should not rethink its policy in light of ISIS' tactics.

"The U.S. policy of not paying ransom to kidnappers is longstanding and it is sound. It would be a mistake of strategic proportions to change that policy," Michael Morell, the former deputy director of the CIA and a CBS News national security analyst, said last month. "If we were to do so, many more Americans would be kidnapped...and we would be become an ATM for militant groups around the world."

Morell noted that many more Europeans than Americans are kidnapped abroad, a likely result of the fact that some European governments will quietly arrange to pay the hefty ransoms demanded for the hostages' release.

Echoing Morell, former U.S. Ambassador to Iraq James Jeffrey told CBS News that practice "inspires [ISIS] to take more hostages."

"They relish in their ability to negotiate with us," he said. "It makes them look like heroes throughout the Middle East.

But it can be a hard argument to swallow when a large cash payment might have saved someone's life. In an interview with Yahoo News, Foley's brother, Michael, said that "more could have been done directly on Jim's behalf."

"I really, really hope that Jim's death pushes us to take another look at our approach to terrorist and hostage negotiation," he said.