China expresses deep condolences over the death of Tanzanian President John Magufuli and sincere sympathies to his family and the government of Tanzania, Chinese Foreign Ministry spokesperson Zhao Lijian said in a statement on Thursday.

Saying that Magufuli attached great importance to developing relations with China and made important contributions to bilateral cooperation in various fields, Zhao hailed him as "an outstanding leader and a staunch defender of national sovereignty against foreign interference."

Magufuli died of heart disease at the age of 61, Vice President Samia Suluhu Hassan announced on Wednesday.

"With great sadness, I announce the death of our brave leader President John Pombe Joseph Magufuli who died today at around 6 p.m.," said Hassan in an announcement televised by state-run Tanzania Broadcasting Corporation. 

Hassan said Magufuli was admitted to the Jakaya Kikwete Cardiac Institute earlier where he was treated for chronic atrial fibrillation, a heart condition he has suffered for more than 10 years. 

According to Tanzania's Constitution, Vice President Hassan shall be sworn in and become the president for the remaining period of the five-year term. 

John Magufuli was reelected president of Tanzania in October 2020. 

Hassan also announced a 14-day national mourning following Magufuli's death. 

"During the 14 days of mourning all national flags will fly at half-mast," said Hassan, adding that funeral arrangements will be announced later. 

Magufuli was born in Chato, Kagera region, on October 29, 1959. He attended several schools for his primary and secondary education, and then enrolled for teacher training at Mkwawa College of Education from 1981 to 1982. 

Magufuli earned his bachelor's degree at the University of Dar es Salaam, majoring in chemistry and mathematics, from 1985 to 1988. He received his doctoral degree in chemistry in 2009, from the same university. 

In 1995, Magufuli was elected member of Parliament in Chato constituency. 

He served as Vice Minister of Works in 1995-2000 and then as the minister in 2000-2005. He also served as Minister of Lands, Housing and Human Settlement Development in 2005-2008, Minister of Livestock Development and Fisheries in 2008-2010, and Minister of Works for a second time in 2010-2015. 

(With input from Xinhua)