Zambia's new president says his country has formally apologized to neighboring Angola for backing a rebel movement that battled Angola's government during a 27-year civil war.

President Michael Sata said Wednesday that he sent an envoy to personally apologize to Angola President Jose Eduardo dos Santos.

During the the 1990s, Mr. dos Santos' party accused Zambia of backing the former rebel group UNITA. At the time, Zambia denied the accusation. The civil war ended in 2002.

President Sata said he sent former president Kenneth Kaunda to Angola. Mr. Kaunda ruled Zambia from independence in 1964 to 1991, when he lost to the late Frederick Chiluba in Zambia's first multi-party elections.

Mr. Sata said during Mr. Chiluba's time as president, Zambia committed “treachery” by backing UNITA rebels in Angola.

Mr. dos Santos has ruled oil-rich Angola since 1979, and he has repeatedly delayed presidential elections since rising to power.