Afghanistan, officially the Islamic Republic of Afghanistan, is a landlocked country situated at the confluence of Western, Central, and Southern Asia. Afghanistan is bordered by Pakistan to the east and south; Iran to the west; Turkmenistan, Uzbekistan, and Tajikistan to the north; and China to the northeast. Occupying 652,000 square kilometers (252,000 sq mi), it is a mountainous country with plains in the north and southwest. Kabul is the capital and largest city. The population is 32 million, mostly composed of ethnic Pashtuns, Tajiks, Hazaras and Uzbeks.