The Lithuanian electricity system (EES), like the EES of Latvia and Estonia, has so far been synchronously operating the IPS/UPS (Integrated Power System/Unified Power System) EES together with the Russian Federation and the Belarusian EES due to historical circumstances. However, in order to achieve the objectives set for the NENS energy sector to move towards synchronous work of the Baltic States with the European continental EES, the existing interconnection between the Baltic States and the IPS/UPS will have to be changed, i.e. the existing 330 kV and 110 kV inter-system lines with the Russian and Belarusian systems will be disconnected. The project “Optimisation and Preparation of the Electricity Transmission Network of North East Lithuania for synchronous work with the Continental European Energy System” will contribute to the preparation of Lithuania’s EES for interconnection with KET in synchronous mode, to the implementation of the strategic interests of the state, the implementation of the energy sector and/or regional energy policies and objectives pursued by the state, to ensure reliable and stable work of the EEU transmission network, the uninterrupted transmission and supply of electricity, the consistent restoration and modernisation of the internal electricity transmission network.