A barge with autotransformer intended for the expansion of the Lithuanian-Polish electricity system connection LitPol Link, moves past the Russian town of Sovetsk, as seen from Panemune, Lithuania May 14, 2021

Lithuania said on Saturday it had disconnected its electricity system from Russia's power grid, part of a plan which the three Baltic states say will integrate them more closely with the European Union and boost security.

Latvia and Estonia are expected to follow suit by 0700 GMT on Saturday and, subject to last-minute tests, the three countries will synchronise with the EU's grid on Sunday after operating on their own in the meantime.

"We have disconnected," a spokesperson for Lithuanian grid operator Litgrid said.

Plans for the Baltics to decouple from the grid of their former Soviet imperial overlord, debated for decades, gained momentum following Moscow's annexation of Crimea in 2014.

The grid was the final remaining link to Russia for the three countries, which reemerged as independent nations after the fall of the Soviet Union, and joined the European Union and NATO in 2004.

The Baltic countries have relied on the Russian grid to control frequencies and stabilise networks to avoid outages. The three staunch supporters of Kyiv stopped purchases of power from Russia following Moscow's invasion of Ukraine in 2022.

Lithuania's energy ministry told it has drawn up contingency plans whereby some heavy energy users, such as factories, could be temporarily disconnected from the grid in the event of power shortages, to maintain essential supplies.