The Islamic State in Iraq and Syria (ISIS) has doubled its presence inside Libya in the last year, the top U.S. military commander overseeing operations in the region said Thursday.
The number of ISIS fighters in Libya doubled to between 4,000 to 6,000 in the last 12 to 18 months, Army Gen. David M. Rodriguez said at a Pentagon briefing.
Rodriguez said the militants aspire to carry out external attacks against Western and U.S. targets, similar to ISIS operations in Iraq and Syria.
"That's been their aspirations all the time, and they are continuing with the same threats that ISIS main is making," he said.
The Obama administration has faced criticism over its ISIS strategy, with Republicans saying more must be done to stop the group.
The administration, though, insists it will defeat ISIS, including outside of Iraq and Syria. Officials are also considering military options inside Libya, according to The New York Times.
The U.S. military conducted an airstrike on Feb. 19 on an ISIS training camp and on Nov. 13 against the senior ISIS leader in Libya. The November strike marked the first U.S. strike against an ISIS leader in Libya.
Rodriguez said the U.S. is Libya is only striking targets that pose an "imminent threat to U.S. personnel and facilities."
"Not the 'intent' to do that — the ones that 'do' that," he said.
Rodriguez said ISIS's largest home in Libya is in and around Sirte, the former home of deposed Libyan dictator Moammar Gadhafi.
"They also have a presence out in the east in Benghazi and Darnah, as well as over in Sabratha in the west," he added.
He said his top concern with ISIS's growing presence in Libya is the challenge it presents to Libya's budding government.
"The government is just getting its feet under itself there," he said. "This is going to take some time for them to, you know move this thing forward."