He is one of three African heads of state meant to be flying to Sudan’s capital, Khartoum, to mediate an end to the fighting.

After five days of bitter battles between the army and the paramilitary Rapid Support Forces (RSF), more than 270 people have been killed.

Mr Ruto urged both sides to immediately ceasefire to allow “unrestricted humanitarian access” and to allow the mediation delegation to land.

"There is real danger that the escalation of hostilities in Sudan could implicate external, regional and international actors and degenerate into a security and humanitarian crisis on a disastrous scale."

Fifteen embassies in Khartoum have called on both sides to protect civilians, diplomats and humanitarian workers.