The United States says it is deeply concerned by possible instability in South Sudan after the president dismissed his vice president and his entire cabinet.

The European Union on Thursday urged all parties to remain calm and resolve political differences through dialogue.

South Sudan President Salva Kiir this week dismissed his vice president and all of his ministers.

Reports of a power struggle in the ruling party have persisted, particularly between Kiir and his first vice president, Riek Macher, who had expressed interest in running for president in 2015. The leader of the ruling party, Pagan Amum, who reportedly also has presidential ambitions, was dismissed as well.

Zachariah Diing Akol, of the think tank Sudd Institute, said his fear is that the dismissals could lead to tribal clashes.

More In: World | International | News