"We have all made it abundantly clear to the South Sudanese parties that they now have a responsibility," Britain's special representative to South Sudan, Chris Trott told RFI on Monday.
"We, the international community have brought them together in Addis Ababa, because we believe that we have an opportunity to bring peace to South Sudan. But our opportunity is their responsibility," he said.
This new phase of peace talks in Addis--dubbed the High Level Revitalisation Forum--have been billed as the last chance for South Sudan's warring factions to find peace.
The government of Salva Kiir said Friday it was willing to participate in discussions with an open heart to end more than four years of conflict, triggered by his sacking of his former deputy, Riek Machar.
Yet expectations are low. Various peace deals have been signed only to be broken later on. The most recent ceasefire--the Cessation of Hostilities Agreement--was signed last December. It was violated almost immediately.
Patience running out
"It's absolutely clear that not just us, but the African Union and others have made it very clear that there will be consequences for those who do not engage meaningfully in the peace process, or undermine the cesssation of hostilities," Trott insisted.
The African Union last week said the "time has come" to sanction anyone who blocks peace, in a sign of growing impatience.
The United States went a step further, announcing a unilateral arms embargo on authorities in Juba, which it deems an "unfit" partner.
"If you're going to impose mass sanctions: asset freezing, travel ban, weapons ban, it has to be done by the region," cautions Kasaija Phillip Apuuli, a politics professor at Makerere University.
"When sanctions were imposed on Burundi under the regional initiative, the sanctions worked because it was the region that imposed them. And eventually the then government of Burundi was forced to go to Arusha and discuss peace with the rebels."
In the case of South Sudan, some observers warn against using a heavy-handed approach.
"While we are putting pressure (...) we should also put ourselves in their shoes," Nhial Tiitmamer, a senior researcher at the SUDD Institute in Juba told RFI.
"We should be realistic and provide incentives like amnesty," he comments, saying "heavy pressure" like the US arms embargo could "backfire."
"This is not to say that I endorse the fact that the parties are using weapons to perpetuate the war," he clarifies, "but it's to say that this could also be counter-productive. By using pressure without room for other alternatives, you're actually pushing the parties to the cliff", he warns.
Yet few are in favour of impunity.
At last month's AU summit, UN ambassador Nikki Haley urged African leaders to "consider seriously the accountability measures it pledged for those who refuse to pursue peace."
Kiir must go
Politics professor Kasaija Phillip Apuuli, agrees. "The leaders of South Sudan have failed their own people," he said.
"If the parties wanted to make peace in South Sudan, they would have made it a long time ago." For him, the African Union, the IGAD regional bloc, and the UN must take "a very firm stand" to "throw out any troublemakers", including President Salva Kiir himself.
"He has demonstrated for the past 5 or 6 years, his incapacity to solve the problem, so he cannot be the solution."
Amid the growing regional and international pressure on South Sudan's government, Salva Kiir is also facing internal woes within his Sudan People's Liberation Movement (SPLM), after his former Chief of General Staff Paul Malong broke ranks, and launched a new rebellion.
"Part of this new momentum is confirmation that Kir couldn't do it," reckons political analyst Joseph Ochieng.
"Some of the key players that were backing Salva Kiir have realized that the result of that is the humanitarian catastrophe, and so what they're suggesting now is a transitional government, in which neither Kiir nor [Riek] Machar is a party."
End in sight
Tens of thousands of people have died and nearly four million South Sudanese have been displaced from their homes since fighting broke out in 2013.
South Sudan's partners are hoping this cycle of violence will come to an end.
The so-called troika of Britain, Norway and the US which plays an influential role in Juba is pushing all parties to honour the 2017 Cessation of hostilities agreement and allow for the talks to make progress.
"We have to be realistic and take it step by step," comments Britain's special representative to South Sudan Chris Trott.
"There is a desire that this should move forward, and I do hope that will be enough to get us to continue the dialougue and find peace," he said.