The main objective of the paper was comparative analyses of natural gas quantities delivered through the existing pipeline capacities in the last decade and new pipeline capacities for the prediction of possible future flows of gas import to Europe. Changes in physical flows have been influenced by European energy strategies that became green oriented resulting with a high amount of non-utilized transmission capacities. The research findings have shown that there is a significant decrease observed in transit of Russian gas through Ukraine in 2020 than previously. Concerning the high increase of LNG import to Europe in the same year, the start of operation of TurkStream, planned start of operation of Nord stream 2, authors project the gradual decrease of transit of Russian gas through Ukraine until the year 2025 with the total stop of transit of Russian gas until the year 2030. The change of supply routes will be also under the economic influence of low gas prices and coal and gas fuel switch until 2030 in the West EU, and after 2030 in the South Eastern European region. In the short-term period transit system for natural gas from Russia via Ukraine will be necessary for supplementing coal with natural gas in the energy mix.