The heads of state and government of Romania, Azerbaijan, Georgia and Hungary have signed an agreement on the construction of an undersea electricity cable under the Black Sea. The ceremony in the Presidential Palace in Bucharest was also attended by EU Commission President Ursula von der Leyen on Saturday. The cable should be completed in three to four years.

After that, it will contribute to the diversification of Europe’s electricity supply. The power from the South Caucasus will also further reduce the continent’s dependence on Russian energy sources. “The two shores of the Black Sea have never been closer,” wrote von der Leyen on Twitter.

President Ilham Aliyev (Azerbaijan) and Prime Ministers Nicolae Ciuca (Romania), Irakli Garibashvili (Georgia) and Viktor Orban (Hungary) had previously signed the document. She is proud that the agreement “places such a strong emphasis on renewable energy,” von der Leyen added.

Georgia and Azerbaijan lie on the Caucasus Mountains. Both countries have significant hydropower potential. Georgia and Romania sit on the Black Sea, while Hungary borders Romania.