The newly established Norwegian site, called Camp Viking, will serve as a hub for Royal Marines Commandos, said Britain's Royal Navy.

It described the troops as "the tip of the Arctic spear" and "the unit the UK turns to when it needs troops able to fight in cold weather extremes.

"A new Arctic operations base will support Britain's commandos for the next 10 years as the UK underscores its commitment to security in the High North," the statement added.

Norway, which borders Russia, refuses to host permanent bases for foreign soldiers, so Camp Viking is due to remain open for just a decade.

The purpose-built base, located around 40 miles (65 kilometres) south of Tromso, will be able to accommodate all personnel from the elite commando-led Royal Marines force which reacts to emerging crises in Europe.

"The camp's location is ideal for deterring threats in the region and situated so the UK can respond rapidly if needed to protect NATO's northern flank and its close ally, Norway," the navy statement said.

Around a thousand commandos have deployed to the base this winter.

In a comment to AFP, Norway's defence ministry said the facility had previously been used by NATO allies and then Dutch Marines.

"The camp is Norwegian and financed through Norwegian infrastructure and operational funds," a ministry spokeswoman said.

A founding member of the North Atlantic Treaty Organization, Norway regularly hosts allied troops for combat training in extreme cold.

The Nordic country, which shares a 123-mile (198-kilometre) border with Russia, has provided Ukraine with a wide range of military equipment, including artillery and ammunition.

The Ukraine conflict prompted its eastern neighbours Finland and Sweden to apply for NATO membership in May 2022, turning the page on policies of military non-alignment in force for decades.