More than 40 South Sudanese soldiers have reportedly arrived in the Democratic Republic of Congo to join an East African force fighting a rebel group.
Some of the 750 troops promised by South Sudan are expected to be flown to Dr. Congo on Monday morning.
They are part of a seven-nation regional force created last June to try to stabilize eastern DR Congo by supervising a withdrawal of M23 rebels.
Rwanda denies it backs the group which has seized large parts of North Kivu province, triggering a humanitarian crisis.