The governments of Uganda and South Sudan signed an agreement extending Ugandan military presence in violence-prone South Sudan for four more months, a Ugandan military spokesman said Wednesday.

A memorandum of understanding was signed on Tuesday in the Ugandan capital, Kampala, between the two countries' ministers of defense, Maj. Henry Obbo said in a statement. The two countries decided it was necessary to renew their military pact because "the situation in South Sudan had not fully stabilized" despite a peace agreement signed on Monday in Ethiopia under the mediation of a regional bloc, the statement said.

Ugandan troops have been fighting alongside troops loyal to South Sudanese President Salva Kiir to put down a rebellion led by former Vice President Machar.

The Ugandan soldiers are based mostly in the capital, Juba, where they protect key sites such as the international airport. Their presence is opposed by rebel forces who say the Ugandans are an obstacle to peace and want them to leave the country.

South Sudan's warring factions have broken multiple agreements pledging a peaceful end to armed conflict in the world's newest country. Watchdog groups have accused both sides of committing rights abuses since violence broke out in December 2013.