The announcement came during UK Defence Minister John Healey's two-day visit to northern Norway amid fears that US President Donald Trump was weakening the US stance on protecting Europe.

The two defence ministers were visiting the British seabed surveillance ship Proteus and the Norwegian coastguard vessel Bison Thursday, both docked in the port of Bodo just above the Arctic Circle.

Norway's Defence Minister Tore Sandvik said his country would bolster its cooperation with Britain -- "Norway's closest and most important ally in Europe" -- notably on protecting subsea infrastructures.

"Russia has for many years maintained and developed its military capacity that can strike Western deep-water infrastructure," he said in a statement.

"We have to expect that this kind of capacity can be used against Norwegian infrastructure in the event of heightened tensions or conflict," he added.

Norway and Britain are connected by two long gas pipelines on the North Sea seafloor.

In 2023, the Scandinavian country supplied more than 30 percent of Britain's gas needs, according to official data.

Several submarine telecoms and electricity cables have been damaged in the nearby Baltic Sea in recent months.

Many European leaders and experts suspect the cable cuts are acts of sabotage, part of a Russian "hybrid war" against Ukraine's Western allies.

"We are now sending a very clear message to anyone thinking of sabotaging our subsea infrastructure: 'We will see you,'" Sandvik said.

On Wednesday, Healey visited the Norwegian town of Kirkenes close to the country's Arctic border with Russia.

"This region reminds us that Russia is a threat well beyond Ukraine and reminds us that Russian aggression is not confined to Ukraine," he said.