East Timor became an independent country on 20 May 2002, marking the end of a three-year process towards independence under the guidance of the United Nations. On that day, the Security Council established UNMISET to provide assistance to East Timor over a period of two years until all operational responsibilities were fully devolved to the East Timor authorities. Subsequently, the Council extended mission's mandate for another year to permit the new nation, which had changed its name to Timor-Leste, to attain self-sufficiency. UNMISET successfully completed its mandate on 20 May 2005 .