NATO Secretary General Jens Stoltenberg and European Commission President Ursula von der Leyen were travelling on Friday to the Troll A platform in the North Sea, which extracts gas from Norway's biggest gas field.

The visit underscores the importance of Norwegian gas towards Europe's energy security. After a drop in Russian flows, the Nordic country last year became the largest gas supplier to the EU.

Stoltenberg and von der Leyen will "discuss the protection and resilience of critical infrastructure and gas supplies to Europe" with Prime Minister Jonas Gahr Stoere and Equinor CEO Anders Opedal, the PM's office said in a statement.

Security at Norwegian petroleum installations was increased after the explosions on the Nord Stream pipelines on Sept. 26 in the Baltic Sea, with NATO allies providing military support.

Troll alone covered 11.3% of EU gas consumption last year, according to operator Equinor. The field accounts for one third of daily Norwegian gas exports to Europe.

Troll's gas is piped to a processing plant on Norway's west coast before it is piped again to the European Union and Britain.