The U.S. has moved surveillance drones into the skies over Libya to gather intelligence and get a better picture of what’s going on in case additional military strikes against Islamic State militants are authorized.

The top U.S. military officer told a Senate committee on Thursday that the Pentagon has shifted assets to Libya, based on recommendations from the U.S. commander for Africa.

The chairman of the Joint Chiefs of Staff, Gen. Joseph Dunford, told the Senate Armed Services Committee that the decision was made more than a month ago to increase resources for U.S. Africa Command.

U.S. officials say the decision allows the Pentagon to shift unmanned aircraft to Libya. Dunford said he agrees with assessments that there are about 6,000 Islamic State militants in Libya.

The rise of the Islamic State in Libya has triggered broad concerns, particularly in Europe. Earlier this month, Army Gen. David Rodriguez, head of U.S. Africa Command, said that the number of Islamic State militants in Libya has doubled in the last year or so to as many as 6,000 fighters, with aspirations to conduct attacks against the U.S. and other nations in the West.

Rodriguez said that local Libya militias have had some success in trying to stop the Islamic State from growing in Benghazi and are battling the group in Sabratha. But he said that decisions to provide more military assistance to the Libyans await a working national government.

Libya slid into chaos following the 2011 uprising that toppled Moammar Gadhafi and has been split between rival governments since 2014. Islamic State militants gained a foothold in Libya amid the power struggle and security vacuum.

The U.S. has conducted two airstrikes in Libya in recent months targeting Islamic State fighters and leaders, but Rodriguez said that those are limited to militants that pose an “imminent” threat to U.S. interests. He said it’s possible the U.S. could do more as the government there takes shape.

The increased surveillance would aid any effort to carry out more of those strikes.

(AP)