"We will substantially contribute, and we will maintain momentum to ensure that the Arctic is reflected in NATO's plans and exercise activities in the long term," Defence Minister Troels Lund Poulsen said in a statement, noting that the details of the support would be determined in coordination with NATO allies.

NATO has said the Arctic Sentry mission will initially pull together undertakings already being carried out by its members in the region, such as exercises by Norway and Denmark.

It remained unclear whether the new mission would involve more military capabilities being sent to the region.

"When the Danish-led exercise Arctic Endurance is integrated into NATO's Arctic Sentry going forward, it will significantly strengthen NATO's northern flank," Danish defence chief Michael Wiggers Hyldgaard said.

Meanwhile Finland, which shares a 1,340-kilometre (833-mile) border with Russia, hailed the NATO initiative as strengthening security in the Arctic, its Ministry of Defence said in a statement.

"It is essential that NATO has strong deterrence and defence in the Arctic and is able to respond in particular to the threat posed by Russia," the ministry said in a statement, adding that China was also seeking to "strengthen its role in the Arctic".

Finnish Defence Minister Antti Hakkanen told AFP Tuesday that he expected "a tough discussion inside NATO" on which countries would be in involved in safeguarding the Arctic and to what extent.