The United Nations has confirmed that it is trying to facilitate the return of South Sudanese opposition leader Riek Machar to the country's capital Juba. International frustration at the delays in the return of the country's First Vice President-designate has been growing as the formation of a Transitional Government of National Unity is seen as a critical step in moving the peace process forward. While the UN would not confirm when it hoped to have Machar on the ground in Juba, there was cautious optimism after the arrival of his Chief of General Staff accompanied by over 100 staff and soldiers aligned to the opposition in the capital on Monday. Sherwin Bryce-Pease reports.