WASHINGTON — The U.S. State Department on Friday approved a pair of potential deals for frigate construction and modernization with Greece, as the Hellenic Navy navigates a complex effort to upgrade its surface fleet.

Greece has an ongoing competition for a three-part plan: upgrade its four Hydra-class MEKO 200 frigates; obtain an interim capability it can operate while the MEKOs are at the maintenance yard; and buy four new frigates. Additional objectives, as outlined to the U.S. Navy, were to involve the Greek industrial base and to increase interoperability with the U.S. as a NATO ally and frequent collaborator in the Mediterranean Sea and elsewhere.