Complex sentence: Since February 17,2004 he has been Vietnam's UN ambassador in New York City; he has held this office from 1995 to 1997 for the UN institutions in Geneva and as a deputy in New York City from 1997 to 1999.
Split into simpler sentences: Since February 17,2004 he has been Vietnam's UN ambassador in New York City. He held this office from 1995 to 1997 for the UN institutions in Geneva and as a deputy in New York City from 1997 to 1999.