The Foreign Affairs Ministry announced Namgyel's appointment to the position in New York.
She is the first woman Foreign Service officer to be elevated to the position of ambassador and the appointment was approved by a 'kasho' or royal decree on January 3.
Namgyel joined the Foreign Affairs Ministry in March 1980 and has served in various capacities, including as Director of the Multilateral Department, Counsellor in Bhutan's Permanent Mission in Geneva and Director at the SAARC Secretariat at Kathmandu in Nepal.