Northeast India (officially called North Eastern Region, NER) is the eastern-most region of India. It comprises eight states – the contiguous Seven Sister States (Arunachal Pradesh, Assam, Manipur, Meghalaya, Mizoram, Nagaland, and Tripura), and the Himalayan state of Sikkim. The Siliguri Corridor in West Bengal, with a width of 21 to 40 kilometres (13 to 25 mi),connects the North Eastern Region with East India, and separates Sikkim from the Seven Sister States. The region shares more than 4,500 kilometres (2,800 mi) of international border with China (Tibet Region) in the north, Myanmar in the east, Bangladesh in the southwest, and Bhutan to the northwest. The region comprises an area of 262,230 square kilometres, 8.0 percent of India.
The states of North Eastern Region are officially recognised under the North Eastern Council (NEC), constituted in 1971 as the acting agency for the development of the eight states. At the time of induction of NEC, the North Eastern Region comprised the Seven Sister States only. Sikkim was introduced as the eighth member in 2002. Sikkim is the least populous and the second smallest state in India.