NATO allies held naval drills off Norway to bolster their Arctic presence near Russia.

Four NATO members have conducted naval exercises in the Arctic waters as part of a broader deployment to patrol the High North, the alliance’s maritime command announced on social media on Monday. Ships from the Netherlands, Norway, Portugal, and Germany took part in manoeuvres off Norway’s northern coast and the High North, aimed at “flexing the Alliance’s ability to work together,” according to NATO’s Allied Maritime Command (MARCOM).

The drills form part of a broader deployment announced last week amid mounting tensions between NATO and Russia.

The operation also aims to secure sea lanes and monitor undersea activity in the Arctic region, a strategically important area home to critical infrastructure, including undersea cables connecting mainland Europe to Norway’s Svalbard archipelago. While NATO maintains a regular eye on northern European waters, it periodically intensifies surveillance and training in the region.

The aim is “to increase the Alliance’s understanding the maritime environment, enhance information sharing, and rehearse navigational manoeuvres,” Commander Arlo Abrahamson, spokesperson for NATO’s Allied Maritime Command, told Euractiv.

The  deployment came just before US President Donald Trump ordered the deployment of two nuclear submarines last week, which has been described as an extraordinary escalation in relations with Russia. It remains unclear whether the submarines are nuclear-powered or nuclear-armed, or where they have been sent. Earlier this year, several members of the Western military alliance conducted an operation involving drones in the Baltic Sea, as incidents targeting submarine cables in the region had begun to increase.