U.S. Secretary of State John Kerry and his counterparts from Ethiopia, Uganda and Kenya have agreed that South Sudan needs a legitimate force to help stabilize the country, which has seen months of deadly violence.
Kerry and the three foreign ministers met Thursday in the Ethiopian capital, Addis Ababa, to talk about how to get neighboring South Sudan's warring sides to agree to halt the fighting.
The United States has already threatened travel and financial sanctions against those responsible for violence that has displaced more than a million people.
A senior State Department official has said Kerry planned to deliver "tough messages" for both the South Sudanese government and rebels during his visit to Africa this week.
State Department spokeswoman Marie Harf said Wednesday that Kerry would use his multi-stop trip in Africa to discuss a range of issues and initiatives, including the U.S. program to help those with HIV and AIDS.
"Addis is the first stop on a week-long trip to Africa to encourage democratic development, promote respect for human rights, advance peace and security, engage with civil society and young African leaders who will shape their continent's future; also promote trade, investment, and development partnerships."
While in the Ethiopian capital, Kerry will hold talks with African Union officials on the Central African Republic, where Muslims continue to flee their homes to escape attacks by Christian militia.
He is also due to meet with Somali President Hassan Sheikh Mohamud to discuss the fight against the al-Qaida-linked militant group al-Shabab.
On Saturday, the secretary travels to the Democratic Republic of Congo's capital to meet with President Joseph Kabila. The two will discuss recent security gains against rebel groups in volatile eastern Congo.
On Sunday, Kerry heads to Angola for a meeting with longtime President Jose Eduardo dos Santos. He returns to Washington on Monday.