WASHINGTON - South Sudan's president dissolved his government Friday and appointed opposition leader Riek Machar as first vice president, one day before the swearing-in of a long-delayed transitional unity government.

In a presidential decree announced Friday on South Sudan state media, Salva Kiir also named Rebecca Nyandeng, widow of South Sudan's founding father, John Garang, as one of five vice presidents, along with Machar, Wani Igga, Taban Deng Gai, and one more person who has yet to be named.

Kiir also issued a decree dissolving his Cabinet and advisory panel. He appointed Tut Gatluak Kew as his presidential adviser on security and Mayik Ayii Deng as minister in the office of the president.

Ethnic divisions and political conflict between Kiir and Machar triggered South Sudan's civil war in December 2013. The war displaced more than 4 million South Sudanese, and hundreds of thousands more have died from fighting, starvation or disease.

Kiir and Machar signed a peace deal to end the war in August 2018. But implementation of the deal was stalled for more than a year until Kiir made a key concession on February 15 and agreed to return the country to its original 10 states. Kiir had unilaterally split the country into 32 states in 2015.

Kiir recently created three "administrative areas," the boundaries and mandates of which are still to be negotiated.

The vice presidents are expected to be sworn in by South Sudan's chief justice Saturday at the presidential palace in Juba. Kiir and Machar will work together in choosing candidates for ministries and state governors.

A similar power-sharing deal that returned Machar to the vice presidency was signed in 2015. But it collapsed a year later following a deadly battle in Juba that killed hundreds and prompted Machar to flee into exile.