LUSAKA - Zambia's interim leader Guy Scott on Wednesday appealed for calm and unity as the southern African country mourns its former president Michael Sata, who died in London on Tuesday night.

Scott, who will act as interim president for the next three months until the country holds a presidential election in accordance with the constitution, said the period of national mourning started on Wednesday but indicated that a detailed program will be availed latter.

In his address to the nation on state television, the interim leader called on people to observe the national mourning period in a peaceful and respectful manner and observe the rule of law.

He said he will diligently oversee the process of electing a new leader in accordance with the country's constitution.

The Zambian Cabinet held a meeting in the wake of Sata's death and picked Scott to be the interim leader, according to Justice Minister Edgar Lungu, who acted as acting president when Sata left for medical check-up in London on Oct. 20.

A parentage clause in the country's constitution, which requires both parents of a presidential candidate should have been born in Zambia, bars Scott from standing as a presidential candidate.

The 70-year-old Scott is of Scottish descent and his parents were not born in Zambia.

He becomes the first white man to rule the southern African nation since it gained independence from Britain in 1964.