Former Tanzania President Benjamin William Mkapa died early Friday at age 81.
President John Magufuli said on television that Mkapa died at a Dar es Salaam hospital where he had been undergoing treatment.
President Magufuli declared a seven-day mourning period that will include flags being flown at half-staff.
Mkapa led Tanzania from 1995 to 2005 before handing over to Jakaya Mrisho Kikwete.
Mkapa also served as Foreign Minister, Minister for Information and ambassador to Canada.