More than 200 people are reported to have died in clashes in recent days
The Minister for Foreign Affairs says the violence in South Sudan 'is deplorable' and 'a betrayal of the people of the country'.
In a statement this evening, Minister Charlie Flanagan also called on all parties to end the violence immediately.
He noted that his Department is in contact with Irish citizens there.
Minister Flanagan said: "I condemn absolutely the attacks on UN personnel and premises, and on humanitarian operations. It is essential that humanitarian actors are allowed to access, without fears for their safety, the vulnerable populations who are in urgent need of assistance.
"The people of South Sudan have been let down too often and have already suffered far too much. There is a particular responsibility on South Sudan's leaders to urgently restore stability and to recommit to full implementation of the Agreement on the Resolution of the Conflict in South Sudan," he added.
South Sudan's president Salva Kiir has ordered a ceasefire following days of clashes in the capital Juba.
More than 200 people are reported to have died, and tens of thousands of civilians are believed to have fled the city.
Feargal O'Connell from Concern is in South Sudan.
"The humanitarian community remain on lockdown [...] That includes the UN," he explained.
"Once there is a calm or a ceasefire, we will be going out to do assessments to look at what the humanitarian needs are."
Concern has said it is implementing the first stages of an emergency response plan.
The UN Security Council has condemned the violence "in the strongest terms" and urged warring groups to control their forces. It also criticised the targeting of UN compounds housing displaced citizens.
The council called on South Sudan's two opposing leaders to “genuinely commit themselves to the full and immediate implementation of the peace agreement, including the permanent ceasefire and redeployment of military forces from Juba”.
The Department of Foreign Affairs has warned Irish citizens against travelling to the country.