South Sudan rebel leader Riek Machar has accused President Salva Kiir Mayardit of frustrating his return to the country.
Mr Machar who President Kiir appointed as his deputy in February failed to show up in Juba for his swearing in ceremony as Deputy President on Tuesday.
He told international television station Al Jazeera the plane that was to airlift him back home had not been cleared to land at Juba Airport.
"I want to go to Juba, I just need permission for the plane to land in Juba," Machar told Al Jazeera on Wednesday.
The two leaders deferred in 2013 after President Kiir accused Mr Machar of planning to overthrow his government in a military coup, prompting Kiir to sack the entire cabinet including Machar and Sudanese People's Liberation Movement Secretary General Pagan Amum.
The development led to fighting which culminated in the displacement of over 200,000 people as rebels allied to Machar clashed with government soldiers in the country's key towns of Bor, Yei, Torit, Yambio and Mandri West.
The two former SPLM fighters signed a ceasefire agreement in 2015 although violent clashes have been witnessed in some parts of the country since then.
The government of South Sudan has a close relationship with Kisumu.
President Kiir in May 2009 visited the lakeside city where he was installed as Luo elder and awarded an Honorary Doctorate at the Jaramogi Oginga Odinga University.
President Kiir during the Kisumu ceremony thanked the Luo community for bestowing him as an elder to lead the people of Southern Sudan to prosperity.
He was given a stool, a stick, a hut, and a traditional bag as a significant indicator of the power of leadership.
During Kiir's swearing in ceremony as President in Juba following the death of South Sudan's first President John Garang de Mabior, Cord leader Raila Odinga led a high profile government delegation to the war-torn nation to witness the event.
Historically, the Luo migrated into Kenya from South Sudan.