U.S. Secretary of State Mike Pompeo said on Monday that Russia is behaving aggressively in the Arctic and China's actions there had to be watched closely as well, amid growing divisions in the polar region over global warming and access to minerals.

Speaking as he arrived in northern Finland for a meeting of nations with territory in the Arctic, Pompeo said China appeared to have national security aims there, and Russia's activities, including plans for new shipping channels from Asia to Northern Europe, deserved a closer look.

"The United States and Arctic nations welcome transparent Chinese investment that reflect economic interests, not national security ambitions," Pompeo said in a speech.