Story highlights The Pentagon says Libya asked the U.S. to help fight ISIS with airstrikes

White House spokesman: U.S. is trying to deny any safe haven for ISIS

(CNN) The United States has expanded its airstrikes against ISIS into Libya, bombing targets in the coastal city of Sirte, U.S. officials said Monday.

The attacks mark the beginning of an ongoing U.S. air campaign in Libya, a Pentagon spokesman said.

The U.S. airstrikes came at the request of the Libyan Government of National Accord, or GNA, to support forces trying to quash ISIS in its primary stronghold in Libya, Pentagon spokesman Peter Cook said. The GNA is Libya's U.N.-backed unity government.

"GNA-aligned forces have had success in recapturing territory from ISIL thus far around Sirte, and additional U.S. strikes will continue to target ISIL in Sirte in order to enable the GNA to make a decisive, strategic advance," Cook said, using another acronym for ISIS.

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"The U.S. stands with the international community in supporting the GNA as it strives to restore stability and security to Libya. These actions and those we have taken previously will help deny ISIL a safe haven in Libya from which it could attack the United States and our allies."

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