Zambia's President Rupiah Banda has set national and local elections for September 20, and will seek his first full term in office.
Banda has also dissolved parliament and his Cabinet as required by law when new polls are announced.
During a nationwide address, Banda said he and the vice president will carry out the duties of the executive branch and that normal government services will continue.
Banda, of the Movement for Multiparty Democracy, has called on candidates to help ensure the elections are free of violence.
The president took power during special elections in 2008, after the death of his predecessor Levy Mwanawasa. During that election, Banda narrowly defeated rival Michael Sata of the Patriotic Front.
Efforts to create an opposition alliance to challenge Banda in the upcoming vote have failed.
The 74-year-old president is expected to benefit from an improved economy in the southern African country, which is the continent's top copper producer.
Some information for this report was provided by AP, AFP and Reuters.