Updated

The United States is urging eastern African nations to quickly send enough peacekeeping forces to South Sudan to quell nearly six months of deadly violence between ethnic groups.

Foreign ministers from Ethiopia, Kenya and Uganda met Thursday with U.S. Secretary of State John Kerry and said they agree aggressive steps must be taken to stop the killings in the world's newest nation.

The diplomats did not offer specifics after their meeting in the Ethiopian capital of Addis Ababa, where Kerry delivered a similar message to African Union officials.

U.S. officials have estimated at least 5,000 troops are necessary for the increasingly bloody mission in South Sudan, where fighting broke out last December after President Salva Kiir, a Dinka, accused former Vice President Riek Machar, a Nuer, of staging a coup.