Foreign investment from other countries (including China, Japan, South Korea, Germany and Russia) has helped to add more paved roads. The most important is a 1000 km north-south road leading from the Russian border at Sukhbaatar to the Chinese border at Zamyn Uud. There are several air transport companies in Mongolia, including MIAT, Aero Mongolia, and Eznis Airways. Petroleum products are mainly (80%)
imported from Russia, which makes Mongolia vulnerable to supply side shocks. This is one strong example of the Influence of Mongolia's neeighbors on its economy.