Gas prices in Europe could spike if Russia's Gazprom and Ukraine's Naftogaz are unable to agree on gas transit from 2020, Mario Mehren, the CEO of Wintershall Dea, said in an interview with the Rossiya 24 TV channel.

Gas prices will definitely rise if this scenario plays out and "price growth could be substantial" given the situation in the cold winter of 2017-2018, when Nord Stream, the Ukrainian gas transmission system and OPAL were working at full capacity.