A consortium led by U.S. oil giant Chevron signed exclusive lease agreements on Monday to explore for natural gas off southern Greece, further expanding the United States' presence in the eastern Mediterranean.

Ukraine’s president says a deal has been reached to open another supply route to secure winter gas imports.

Greece has named a consortium of U.S. oil major Chevron and the country’s largest oil refiner, Helleniq Energy, as the preferred bidder for offshore gas exploration in southern Greek waters, the energy ministry announced on Friday.

The Trans Adriatic Pipeline (TAP) has transported 40 billion cubic meters (bcm) of natural gas from Azerbaijan to Europe over the past four years.

Azerbaijan’s Minister of Energy Parviz Shahbazov on Thursday announced the country’s plan to export 1.2 bcm of gas to Greece by the end of 2024.