VIETNAMESE president Tran Dai Quang has died at the age of 61 after a serious illness, the government said.

Quang died despite “utmost efforts to treat him by Vietnamese and foreign professors and doctors and care by the party and state leaders”, the statement said.

It said Quang – the country’s number two after the ruling Communist Party leader – died at a military hospital in Hanoi, but did not elaborate on his illness.

One state-run online newspaper quoted the former health minister Nguyen Quoc Trieu as saying Quang had contracted a rare and toxic virus in July last year.

Trieu said the president lapsed into a deep coma hours after being admitted to the National Military Hospital 108 on Thursday afternoon.

“Japanese professors and doctors treated him and helped consolidate the president’s health for about a year,” Trieu said. “However, there are no medicines in the world that can cure the illness completely, instead it only could prevent and push it back for some time.”

Quang’s last public appearance was at a reception for a Chinese delegation on Wednesday. He looked frail on the state-run Vietnam Television broadcast.