The President of Nauru, Bernard Dowiyogo died at the George Washington University Hospital in Washington DC yesterday.
Mr Dowiyogo, who was 57, had undergone an eleven hour heart operation on Tuesday last week.
A Nauru Government spokesperson says the United States Air Force has agreed to fly Mr Dowiyogo's body back to Nauru later this week for a funeral service.
Mr Dowiyogo, who has been a diabetic for 30 years, underwent coronary artery bypass surgery in Melbourne in 2001 and required alternate day dialysis.
His Melbourne doctor told AAP that he collapsed while on official business in Washington and was rushed to the hospital.
In January, he replaced Rene Harris as President.
It was sixth time since 1976 that he had been Nauru's President.