ATHENS, Greece — The leaders of Greece and Bulgaria have announced plans to expand natural gas cooperation with a deal that could help other countries in the region lower their dependence on Russian energy.

Under an agreement signed in Athens Thursday, Greece will gain access to Bulgaria’s gas storage facilities in exchange for expanded use by Bulgaria of a liquefied natural gas terminal near Athens.

Russian supplier Gazprom halted gas deliveries to Bulgaria over a pay mechanism dispute last April, two months after Russia launched its invasion of Ukraine. Greece has also drastically reduced Russian gas imports over the past year.

“For one year now, Russian (aggression) has been held back by the brave defense of the Ukrainian people, but it continues to cause economic pain by turning energy into a means of blackmail,” Greek Prime Minister Kyriakos Mitsotakis said after meeting President Rumen Radev of Bulgaria.

“The only option we have is to speed up our effort to reduce our need for Russian gas.”

Thursday’s agreement was signed four months after Greece and Bulgaria completed a natural gas grid pipeline connection, giving Bulgaria access to the LNG market through Greek port access.

The European Union and the United States strongly supported the landmark project that could also help other Balkan countries lower their dependence on Russian gas, helped by continued pipeline system modification in the region.