ATHENS, Greece (AP) — Exxon Mobil is poised to start a delayed gas prospecting project off southwestern Greece, the country's leader said Monday amid tensions between Greece and Turkey over offshore rights and as Europe seeks alternative energy sources due to the war in Ukraine.

The U.S. energy giant will start seismic exploration “in the coming days” southwest of the southern Peloponnese peninsula and the island of Crete, Prime Minister Kyriakos Mitsotakis told private Antenna TV.

The project has been heavily criticized by environmental groups, which argue that the deep-sea prospecting would have “unbearable” consequences on endangered Mediterranean whales and dolphins. Critics also highlight the potential risk of spills, and say the project, if successful, would increase Greece's use of fossil fuels amid the planet's climate change crisis.

Mitsotakis insisted Monday that Greece remains dedicated to “fast green transition.” But he added: “Our country ... must ascertain whether it currently has the ability to produce natural gas, which would contribute not only to our own energy security but also to that of Europe.”

European countries are scrambling to replace their former dependency on Russian fossil fuels following Russia's Feb. 24 invasion of Ukraine and the subsequent damaging of pipelines designed to bring natural gas from Russia to Germany.

Meanwhile, Greece and Turkey are at loggerheads over offshore exploration rights in the eastern Mediterranean, and Turkish prospecting east of Crete in 2020 prompted a military build-up and bellicose rhetoric.

In 2019, Greece granted rights for exploration — which, however, didn't go ahead — in two blocks of seabed south and southwest of the island of Crete to a consortium of TotalEnergies and Exxon Mobil with Greece’s Hellenic Petroleum.

The areas include the Mediterranean’s deepest waters. The Hellenic Trench, at 5,267 meters (17,300 feet) is a vital habitat for the sea’s few hundred sperm whales, and for other cetaceans already threatened by fishing, collisions with ships and plastic pollution.

These mammals are particularly sensitive to the underwater noise produced by seismic surveys for fossil fuels, in which sound waves are bounced off the seabed to locate potential deposits. Sonar used by warships has been shown to have deadly effects on whales, and experts say seismic surveys can do the same.

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