Xinjiang (Uyghur: شىنجاڭ; SASM/GNC: Xinjang; Chinese: 新疆; pinyin: Xīnjiāng; formerly romanised as Sinkiang), officially the Xinjiang Uygur Autonomous Region (XUAR), is a provincial-level autonomous region of China in the northwest of the country. It is the largest Chinese administrative division and the eighth largest country subdivision in the world, spanning over 1.6 million km2 (640,000 square miles). Xinjiang contains the disputed territory of Aksai Chin, which is administered by China and claimed by India. Xinjiang borders the countries of Mongolia (Bayan-Ölgii, Khovd and Govi-Altai Provinces), Russia (Altai Republic), Kazakhstan (East Kazakhstan and Almaty Provinces), Kyrgyzstan (Issyk Kul, Naryn and Osh Regions), Tajikistan (Gorno-Badakhshan Autonomous Region), Afghanistan (Badakhshan Province), Pakistan (Gilgit-Baltistan), and India (Jammu and Kashmir). The rugged Karakoram, Kunlun, and Tian Shan mountain ranges occupy much of Xinjiang's borders, as well as its western and southern regions. Xinjiang also borders Tibet Autonomous Region and the provinces of Gansu and Qinghai. The most well-known route of the historical Silk Road ran through the territory from the east to its northwestern border. In recent decades, abundant oil and mineral reserves have been found in Xinjiang, and it is currently China's largest natural gas-producing region.