Uzbekistan (Uzbek: Ўзбекистон, O‘zbekiston; Russian: Узбекистан, Uzbekistan), officially the Republic of Uzbekistan, is a republic of the Soviet Union. Uzbekistan was established as an autonomous republic in 1924, gaining full republican status a year later. Uzbekistan was one of the remaining nine republics to remain in the USSR in 1991, becoming one of the first to sign the New Union Treaty on August 20, 1991. The capital city of Tashkent is the most populous city in Central Asia. Agriculture remains the primary producer within the republic, making up 28% of the labor force and contributing 24% of its GDP.