For several months we have seen the presence of Russian forces in eastern Ukraine, as well as a substantial increase in Russian heavy equipment such as tanks, artillery and advanced air defence systems.

Russian troops in eastern Ukraine are supporting these offensive operations with command and control systems, air defence systems with advanced surface-to-air missiles, unmanned aerial systems, advanced multiple rocket launcher systems, and electronic warfare systems. http://www.nato.int/cps/en/natohq/news_116852.htm