Norway has summoned the Russian ambassador in Oslo for an explanation after a top Russian official defied a travel ban by visiting Arctic Norway.
Deputy Prime Minister Dmitry Rogozin flew to Svalbard, in the Arctic Circle, then went to the North Pole to open a Russian drifting base on an ice floe.
Russia is boosting its Arctic presence.
Mr Rogozin has been blacklisted by the EU, US and Norway since Russia’s 2014 annexation of Crimea. The sanctions bar visits or use of Western banks.
The Russian foreign ministry reacted angrily (in Russian) to Norway’s stance on the visit, calling it “inexplicable and absurd from the perspective of international law”.
It said the current sanctions “have nothing to do with” the 1920 Spitsbergen Treaty, which “provides free access to the archipelago for signatories to the treaty”.
“Norwegian law was not violated either” by Mr Rogozin’s visit, the ministry said.
Mr Rogozin heads a new Russian government commission overseeing projects in the Arctic. In 2015-2020 Russia plans to spend 222bn roubles (£2.8bn; $4.3bn) on developing Russia’s resources in the Arctic, which is believed to be rich in untapped energy and minerals.
In February, government newspaper Rossiiskaya Gazeta quoted him as saying development of the Arctic shelf would lead inevitably to a conflict of interests between nations, and he did not rule out such a confrontation escalating beyond diplomatic disputes.
Russia is among Arctic nations that have submitted claims to Arctic territory – claims now being considered by a UN arbitration panel.
In tweets, Mr Rogozin shrugged off Norway’s displeasure at his visit to Svalbard on Sunday. Russia has a small coal-mining community at Barentsburg in the Norwegian archipelago, which he visited.
He also sent pictures and triumphant comments from Russia’s new North Pole Station-2015. He flew there aboard a special plane from Longyearbyen, which has Svalbard’s only airport.
“The Arctic is Russian Mecca,” he tweeted in English.
Earlier he tweeted: “Norwegians bring their tourists here in snowmobiles to explore the ‘Soviet heritage'”, “I just took a dip in the Arctic Ocean” and – in an ironic comment on the Norwegian protest – “you don’t wave your fists after a fight”.
The Russian polar base is on a drifting ice floe, and revives a Russian programme of drifting Arctic stations that was suspended in 2013, Tass news agency reports.
Russia’s first North Pole station was opened in 1937, in Soviet times.