Ruto said he spoke to Kiir on Saturday and urged him to facilitate dialogue for all involved parties to stop the fighting.
Kenya has also asked the international community to intervene and help in the growing instability in South Sudan.
“As a neighbor and grantor of the South Sudan Peace process, I, on behalf of Kenya, bring these concerning developments to the attention of the wider international community and call for a focus and immediate intervention geared towards de-escalation, peaceful resolution and coexistence among the parties involved,” Ruto said.
The fighting has displaced thousands of people and left many in dire need of water, food, shelter and medical aid.
This is the second time Kenya is sending food and medical aid to South Sudan following a similar donation on Nov. 25.
The larger east African region is facing the worst drought in decades with some areas experiencing five failed consecutive rainy seasons while others have below average rainfall.
Kenya shares its northern border with South Sudan and plays a key mediation role in the implementation of the country’s peace agreement.
There were high hopes when oil-rich South Sudan gained independence from Sudan in 2011 after a long conflict. But the country slid into civil war in December 2013 largely based on ethnic divisions when forces loyal to Kiir battled those supporting Machar.
Tens of thousands of people were killed in the war, which ended with the 2018 peace agreement. But the terms of that accord have not been fully implemented, and persistent violence is weakening it even more.
