Norway's foreign ministry on Thursday said it had decided to expel 15 Russian embassy officials, adding that they were intelligence officers operating under the cover of diplomatic positions.

"The government's decision is in response to the changed security situation in Europe, which has led to an increased intelligence threat from Russia," the foreign ministry said in a statement. "The officers concerned must leave Norway shortly."

The Russian embassy in Oslo was not immediately available for comment when contacted by Reuters.

Norway, a member of the NATO military alliance, shares a border with Russia in the Arctic.

"This is an important step in countering, and reducing the level of, Russian intelligence activity in Norway, and thus in safeguarding our national interests," Norway's Foreign Minister Anniken Huitfeldt said. (Reporting by Terje Solsvik and Nerijus Adomaitis, editing by Gwladys Fouche)