Tran Dai Quang passed away in a Hanoi military hospital at 10:05am local time (3:05am GMT) on Friday. The Vietnamese leader was 61 years old.
He took office in April 2016 after serving as head of the ministry of public security, and was one of the top members of the decision-making body of the Communist Party of Vietnam, the Politburo.
Speculation over the health of one of the highest officials in the communist country grew in recent months as Quang disappeared from the public eye and missed several meetings and key events. After a nearly one-month disappearance, he met Herminio Lopez Diaz, the departing Cuban ambassador, in Hanoi in August. Two weeks later, Quang was reportedly visibly unwell and stumbled during a visit by Indonesian President Joko Widodo on September 11.