Nkurunziza died on June 9 following a cardiac arrest.
East African member states will fly their flags at half-mast to honour Burundi's President Pierre Nkurunziza who died on Tuesday, the presidents said separately.
Kenya’s President Uhuru Kenyatta on Friday directed that the Kenyan flag and that of the East African Community be flown half-mast from Saturday, June 13 from dusk until dawn at all public buildings and public grounds, and at all of Kenya’s Diplomatic Missions abroad.
President Kenyatta mourned President Nkurunziza who died on June 9 at the age of 55 following a cardiac arrest.
“May the late President Pierre Nkurunziza rest in eternal peace,” the statement read.
In Rwanda, a communique signed by Prime Minister Edouard Ngirente on Saturday said that President Paul Kagame had directed that the Rwandan and East African Community flags be flown at half-mast in the country from Saturday June 13 until the day Nkurunziza is buried.
“We continue to grieve with the People of Burundi and the family of His Excellency Pierre Nkurunziza during this difficult time,” the statement said.
Tanzania's President John Magufuli declared three days of mourning in Tanzania from Sarturday to mourn Mr Nkurunziza. The Tanzanian national flag will fly at half-mast during this time.