Gazprom does not sell more volume of gas because of the domestic market
The reduction of supplies to Europe is impossible because of long-term contracts. The Global Energy Policy Centre published its gas investigation in the USA, Europe and Russia in future. It is said that the USA in any case can not replace Russia on the European market.
As it became known recently, the share of Russia in Europe makes up about 65%. There might be exported about 50 billion cubic meters of gas from the USA to the global market in 2025 with luck. The total volume of export from Russia to Europe makes up approximately 150 billion cubic meters. The maximum possible loss from pipeline gas export substitution by American LNG makes up about 20% at the worst case senario.
The Europe itself can not reject Russian gas because of natural causes and current contracts. The contractual obligations bind some countries until 2027 and they are to buy not less than 100 billion cubic meters of gas.