Serbian President Aleksandar Vucic and Russian President Vladimir Putin are meeting in Moscow to discuss a strategic partnership between Russia and Serbia , Tass reported Dec. 19. Their meeting will address a range of international and regional issues that involve energy cooperation, culture, politics, economics and trade. The countries are expected to enter into a variety of bilateral agreements, including Serbia's purchase of at least six military transport helicopters and air defense systems from Russia. Vucic said he will also confirm Serbia's refusal to join NATO and its opposition to sanctions being imposed on Russia by the West .