The US Ambassador, Mr Timothy Roemer, has decided to resign due to personal commitments.
According to US embassy sources, 54-year-old Roemer, a political appointee, wants to go back to Washington due to some personal considerations. Other reasons that may have prompted him to take the step were not known.
However, Mr Roemer had indicated at the time of taking up the assignment in 2009 that he would stay for a couple of years and then move on. A formal statement on his decision is expected to be issued later in the day.
Mr Roemer was nominated by the US President, Mr Barack Obama, in May 2009.