Kazakhstan or Kazakstan (kä"zäkstän') [key], officially Republic of Kazakhstan, republic (2005 est. pop. 15,186,000), c.1,050,000 sq mi (2,719,500 sq km), central Asia. It borders on Siberian Russia in the north, China in the east, Kyrgyzstan, Uzbekistan, and Turkmenistan in the south, and the Caspian Sea and European Russia in the west. Astana is the capital and Almaty (Alma-Ata) is the largest city. Other major cities include Shymkent, Semey, Aqtöbe, and Öskemen.