VILNIUS, July 17 (Reuters) - The Baltic states will decouple from the Russian power grid in early 2025, Estonian Prime Minister and Lithuanian power grid operator CEO said.

"As a compromise, we're (are) agreeing to bring this deadline a year closer. So, leaving in the beginning of 2025," Estonian Prime Minister Kaja Kallas told Reuters on the sidelines of NATO summit in Vilnius last week.

Three decades after splitting from the former Soviet Union and 19 years since joining the European Union, the Baltic states of Estonia, Latvia and Lithuania still depend on Russia to ensure a stable power system.

Under a deal signed in 2018, the leaders of the region, as well as Poland and the European Commission backed by 1.6 billion euros ($1.61 billion) in European funding, agreed to upgrade their infrastructure and disconnect from the grid by 2025.

Lithuania has been proposing to move the decoupling date to early 2024, but this was not acceptable to Estonia, said Kallas.

"I understand that Lithuania wants to have it faster, but the question is that ... Estonia would pay the highest price for this (earlier decoupling) in terms of the (cost), but also in terms of risks of blackouts," said Kallas.

The decoupling will be announced by a formal application to the Baltic, Russian and Belarus joint grid operators in August 2024, she added.

Lithuania would follow the timetable preferred by Estonia, as it cannot decouple alone, Rokas Masiulis, the chief of the Lithuanian power grid operator Litgrid, told reporters on Monday.

"We are tied with a chain (with Estonia)," he said, adding Lithuania would continue to ask its neighbours to move sooner: "We see what happens in Ukraine, where people are being killed and bombs continue to fall – I don't think it's the right choice to keep cooperating with the aggressor just because this saves a few cents." (Reporting by Andrius Sytas in Vilnius; editing by David Evans)