Ethiopian Foreign Minister Adhanom Tedros commented on the start of the face-to-face peace talks on social media, posting to Facebook and Twitter.
On his Facebook page, the foreign minister wished the two parties well in their efforts to secure peace.
The foreign minister re-tweeted a photo of himself on a stage with Kiir and Machar at the opening of the official peace talks on Saturday.
Violence broke out in South Sudan in mid-December when President Kiir accused his fired deputy, Machar, of attempting a coup. Forces loyal to the two men engaged in violent conflict over the past three weeks, resulting in the deaths of thousands and the displacement of 180,000. African leaders from the Intergovernmental Authority on Development engaged in mediation efforts, which imposed a December 31, 2013 deadline for Kiir and Machar to meet face-to-face. Representatives of both men traveled to Ethiopia by the deadline to engage in peace talks.