According to Interfax, the ceremony to mark the start of work on May 3 will be attended by European Council President Charles Michel, Serbian President Aleksandar Vučić, Bulgarian and North Macedonian Prime Ministers Kiril Petkov and Dimitar Kovachevski.

"The floating LNG terminal at Alexandroupoli will help achieve the EU's goal of phasing out Russian gas as soon as possible, as decided by the European Council in March," Barend Leiths, spokesman for the European Council President, said in a statement.

Greek Prime Minister Kyriakos Mitsotakis said earlier that the European economy cannot completely abandon the supply of Russian natural gas.

Hungarian Foreign Minister Peter Szijjarto said that some European companies importing Russian natural gas agreed to the payment scheme proposed by Moscow, but not everyone is honest about it.