The Russian Foreign Ministry has warned that Moscow could take countermeasures if the US proceeds with modernisation of the radar facility Globus 2 in Norway's Vardo municipality.
Foreign Ministry spokeswoman Maria Zakharova said that Moscow has every reason to believe that the radar facility will be used for surveillance purposes against Russia.
The official also added that the radar station would become part of the US anti-ballistic missile system.
"There is every reason to believe that the radar will monitor specifically the Russian territory and will become part of the US global missile defense network," Zakharova said. "It is obvious that the military preparations of this kind… be it near the Russian border or another border, cannot be ignored by our country or any other country. Accordingly, we are considering reciprocal measures that will be taken to ensure our own security".
Zakharova noted that Russia has repeatedly been denied consultation on this issue by the Norwegian authorities.
The US-funded Globus II station on the Arctic island of Vardo is located only 50 kilometres from the border with Russia and is staffed by the Norwegian military intelligence personnel.
In April 2016, the Norwegian Army announced modernisation of the radar station scheduled for 2017-2020. The facility is expected to include another radar.
Moscow has repeatedly voiced concern over NATO's build-up along its borders and in Europe. THAAD is an anti-ballistic missile defence system that intercepts ballistic missiles during their late mid-course or final stage flight both inside and outside the Earth's atmosphere.