The ousting of Yanukovych prompted Vladimir Putin to begin preparations to annex Crimea on 23 February 2014. Using the Russian naval base at Sevastopol as cover, Putin directed Russian troops and intelligence agents to disarm Ukrainian forces and take control of Crimea. After the troops entered Crimea, a controversial referendum was held on 16 March 2014 and the official result was that 97 percent wished to join with Russia. On 18 March 2014, Russia and the self-proclaimed Republic of Crimea signed a treaty of accession of the Republic of Crimea and Sevastopol in the Russian Federation. The UN general assembly responded by passing resolution 68/262 that the referendum was invalid and supporting the territorial integrity of Ukraine.