Kerry, African ministers to meet on South Sudan violence, Somalia

Machar was picked up by U.N. peacekeepers in the neighboring Democratic Republic of Congo a week ago with a leg injury and was handed over to authorities in Congo.

Machar led a two-year rebellion against forces loyal to rival Kiir before the two sides reached a peace deal in August 2015. Under the deal, Machar returned to Juba in April to resume his role as vice president.

On Monday, Kerry will meet Kenyan President Uhuru Kenyatta before joining foreign ministers from Kenya, Uganda, South Sudan, Sudan, Djibouti, Tanzania, Somalia and Ethiopia to discuss South Sudan and Somalia, where there are concerns that delays in the approval of new election rules could dampen its recovery from conflict.

World powers and regional states have struggled to find leverage over the warring factions in South Sudan, despite U.S. and European sanctions on some military leaders and African threats of punitive actions.

Especially of concern to Washington was an attack on a Juba hotel in July by uniformed men who killed a U.S.-funded journalist and raped civilians, including aid workers.

The U.N. has launched an investigation into accusations U.N. peacekeepers in Juba failed to respond properly to the attack.

In Kerry's talks with Kenyatta, he will also discuss Kenya's presidential election set for August 2017, the senior State Department official said.

Opposition protests in Nairobi since April have stoked fears among church leaders and Western diplomats of a repeat of the violence following the 2007 election in which 1,200 people were killed.

In a letter to Kerry before his visit, the Human Rights Watch group urged him to discuss rights concerns with Kenyatta. The group said it had documented 34 cases of extrajudicial killings and another 11 deaths of people last seen in state custody over alleged links with al-Shabaab militants in Nairobi and in the northeast.