Europe's biggest gas firms say the continent's top supplier, Gazprom, is fulfilling its long-term contracts, yet the Russian energy giant remains at the center of a dispute about whether it could do more to ease the price pain in a red-hot spot market.

The rocketing price of gas, with the European benchmark up almost 600% this year, fueled by low inventories and surging demand in Asia and elsewhere as economies recover from the COVID-19 crisis, has put Gazprom in Europe's crosshairs.

The Russian gas export pipeline monopoly, which supplies 35% of European needs, insists it is meeting contracted commitments — which top European clients have confirmed to Reuters.