The European Union wants member states to buy more gas from countries other than Russia to reduce reliance on Russian supplies at risk of disruption due to the invasion of Ukraine. The 27-country EU relies on Russia for 40% of its gas.

"Europe is an empty box in term of energy," Descalzi said at an industry event in the United Arab Emirates. "We don't have our own energy... And we never thought about a strategy for energy security."

Descalzi said the gas supply issue was a big one for Europe, noting that Russia is asking Eni to pay for gas in roubles, which is not in the contracts.

"It's difficult to agree because we don't have this kind of currency," Descalzi said. "For seven years we underinvested ... The worldwide leadership was not wise and without any equilibrium in evaluating the energy situation."

The Russian central bank, the government and Gazprom, which accounts for 40% of European gas imports, have to present their proposals for rouble gas payments to President Vladimir Putin by March 31.

Energy ministers from the Group of Seven industrialised nations have rejected the rouble payment demands,

(Reporting by Riham Alkoussa; Writing by Nadine Awadalla; Editing by Louise Heavens and Jane Merriman)