Kenya's President Uhuru Kenyatta says he's learned "with profound sorrow" and sadness the death of Tanzania President John Magufuli.

He has conveyed his condolences to widow Janet Magufuli, the government and people of Tanzania.

President Kenyatta said Mr Magufuli was a champion of pan-Africanism.

"I have lost a friend, colleague and visionary ally," he said.

Mr Kenyatta, who is the current chairman of the East African Community, has declared a seven-day period of national mourning in Kenya.

He said the flag of the East African Community and Kenya’s flag would be flown at half-mast throughout Kenya and all its diplomatic missions abroad until sunset on the day of Mr Magufuli's funeral.