A senior official who is the de facto number two of the Communist Party has taken sick leave to seek treatment for an unspecified disease.
Dinh The Huynh has run the influential Central Committee Secretariat since February 2016.
The Party announced on Tuesday that it has deputized Tran Quoc Vuong, chairman of the Central Inspection Committee, to take charge in Huynh's absence.
The Secretariat oversees the Party's day-to-day policy implementation. Both Vuong and Huynh are members of the elite Politburo, the Party’s decision-making body.
It is not clear how long Huynh will be out of action for. Before taking charge of the Secretariat, he headed the Party’s propaganda body.
Vuong was Vietnam’s top public prosecutor until 2011, when he was installed as Chief of Staff of the Party’s Central Committee. He was selected to chair the Central Inspection Committee in January 2016.