UNITED NATIONS -- Wu Hongbo, a senior Chinese diplomat, has been officially sworn in as UN under-secretary-general for economic and social affairs here on Monday.

The inauguration ceremony, hosted by the UN Secretary-General Ban Ki-moon, was held at the UN headquarters.

Wu, who was Chinese ambassador to Germany since 2009, was appointed by Ban in May as the under-secretary-general for the UN Department of Economic and Social Affairs.

He is successor to Sha Zukang who held this position since 2007.