<Table> <Tr> <Th_colspan="2"> Secretary - General of the United Nations </Th> </Tr> <Tr> <Td_colspan="2"> Emblem of the United Nations </Td> </Tr> <Tr> <Td_colspan="2"> Flag of the United Nations </Td> </Tr> <Tr> <Td_colspan="2"> Incumbent António Guterres since 1 January 2017 (2017 - 01 - 01) </Td> </Tr> <Tr> <Td_colspan="2"> United Nations Secretariat </Td> </Tr> <Tr> <Th> Style </Th> <Td> His Excellency </Td> </Tr> <Tr> <Th> Status </Th> <Td> Chief administrative officer Head of an organ </Td> </Tr> <Tr> <Th> Member of </Th> <Td> Secretariat General Assembly </Td> </Tr> <Tr> <Th> Residence </Th> <Td> United Nations Headquarters </Td> </Tr> <Tr> <Th> Seat </Th> <Td> New York City, New York, United States </Td> </Tr> <Tr> <Th> Nominator </Th> <Td> Security Council </Td> </Tr> <Tr> <Th> Appointer </Th> <Td> General Assembly </Td> </Tr> <Tr> <Th> Term length </Th> <Td> five years, renewable (traditionally limited to two terms) </Td> </Tr> <Tr> <Th> Constituting instrument </Th> <Td> United Nations Charter </Td> </Tr> <Tr> <Th> Inaugural holder </Th> <Td> Gladwyn Jebb as acting Secretary - General (24 October 1945) Trygve Lie as first Secretary - General (2 February 1946) </Td> </Tr> <Tr> <Th> Formation </Th> <Td> 24 . October 1945 </Td> </Tr> <Tr> <Th> Deputy </Th> <Td> Deputy Secretary - General of the United Nations </Td> </Tr> <Tr> <Th> Website </Th> <Td> un.org/sg </Td> </Tr> </Table> <Tr> <Th_colspan="2"> Secretary - General of the United Nations </Th> </Tr>

Who is the chief administrative officer of the un