Zambia's President Michael Sata
Zambia's President Michael Chilufya Sata addresses the 68th United Nations General Assembly at the UN headquarters in New York, in this on Sept. 24, 2013 file picture. Reuters/Justin Lane

President Michael Sata of Zambia has reportedly died at London’s King Edward VII hospital where he was receiving treatment for an undisclosed illness. Defense Minister Edgar Lungu had been named as acting president and was running the country while Sata was out of the country.

The Zambian cabinet, which is set to meet on Wednesday, may now discuss the country's future leadership, BBC reported. Earlier this month, several rumors had circulated in Zambia about Sata's health. The 77-year-old leader was last seen in public in September, when he returned from the U.N. General Assembly headquarters in New York, where he failed to deliver a scheduled speech.

"It is true. We lost the President. The acting president will make a statement soon," a government source told Reuters.

The Zambian constitution requires a presidential election to be held within 90 days and the country is expected to be led either by Lungu, or Guy Scott.

The latter, if he wins, would become the first white head for an African country since South Africa’s FW de Klerk stepped down in 1994. But, analysts suggest that Scott may not take part in the elections due to citizenship restrictions, Reuters reported.

Sata, who came to power in 2011, had left for London for treatment on Oct. 19 with his wife and other family members.