A team from the African Union headed by former Malian President, Alpha Omar Konare, is in Juba to follow up on the implementation of the peace agreement, according to the office of the President.
They are expected to meet with President Salva Kiir tomorrow.
Both the government and the SPLM in Opposition forces accuse each other of violating the ceasefire that came into force at mid night on Saturday.
Clashes have been reported in Upper Nile, Unity and Jonglei State.
The US has threatened further UN sanctions due to the violations.