ANKARA — Turkey is providing support to Libyan authorities in taking legal action against a deal between Greece and Chevron for offshore hydrocarbon exploration in the Eastern Mediterranean, a Turkish defense official said Thursday.

The deal: Energy giant Chevron on Monday signed lease agreements with Athens and Helleniq Energy, Greece’s largest oil refiner, to explore four offshore blocks — including two south of Crete, Greece’s largest island in the Eastern Mediterranean, and two near the Peloponnese, the large peninsula forming southern mainland Greece.

A Turkish defense official on Thursday described the deal as “running counter” to a 2019 maritime agreement signed between Ankara and Libya’s Tripoli-based government that delineates maritime boundaries between the two countries and grants both sides rights to explore and exploit offshore resources.

“We will continue to provide the necessary support for Libyan authorities to take action against Greece’s unilateral and unlawful activities,” the official said on condition of anonymity at a background briefing in Ankara.