Heads of state meeting in Kigali for the African Union summit are set to weigh a potentially historic decision regarding military intervention in South Sudan, even as President Salva Kiir is warning that more foreign troops would not be welcome in the country.

The AU has endorsed a call by the Intergovernmental Authority on Development for the strengthening of the United Nations Mission in South Sudan (Unmiss). The AU declaration states that the revamp should include the establishment of an “African-led” combat brigade to put an end to South Sudan’s renewed civil war.

“The ball is now in the African Union’s court,” said Prof Alex de Waal, a South Sudan expert who heads a world peace institute at a US university.

The AU has its own African Standby Force intended to be deployed in crises such as the outbreak of mass killings last week in Juba.

But President Kiir, reacting to proposals by opposition leaders that the capital Juba be run by Unmiss, that the country be placed under UN trusteeship and he and First Vice President Dr Riek Machar resign, vowed not to allow additional foreign troops in the country.

“There are over 12,000 foreign troops here. Why do you need more forces?” he asked. “What will they come and do?”

The US is understood to be offering to help pay 75 per cent of the cost of an AU-led intervention brigade in South Sudan if African states agree to finance the remaining share.

The UN says it plans to work with the AU and Igad in assembling an intervention brigade for South Sudan and in expanding the Unmiss deployment from its current level of 13,500 soldiers and police.

Unmiss should also be equipped with attack helicopters and surveillance drones, UN peacekeeping chief Herve Ladsous told the Security Council last week.

Meanwhile, it appears possible that the warring sides in that country will be hit with an arms embargo and additional sanctions within the next few weeks.

The Security Council may agree to initiate both an arms ban and new sanctions when it considers extending and expanding Unmiss’s mandate later this month or in August.

But Juba is strongly opposed to the imposition of a UN arms embargo.

“Do they want our national army to carry sticks?” South Sudan ambassador to Kenya Chol Mawut Unguec Ajonga asked rhetorically in an interview with the BBC last week.

Juba also does not want the UN or the US to levy sanctions on additional government officials. The UN has previously placed financial sanctions on six South Sudanese figures said to be responsible for human rights violations. The US has taken such actions against four of those individuals.

A key question now is whether the UN and the US will decide to single out the principals — President Kiir and Vice President Machar — for sanctions, given their violations of the hard-won peace agreement they signed 11 months ago.

Blaming the armed factions

Opposition leaders believe they should. Dr Lam Akol, an opposition leader, recently called on the authorities to hand over to Unmiss the security of the capital Juba, blaming the armed factions of President Kiir and Dr Machar for breaking the peace agreement.

A member of former political detainees group, Pagan Amum, also called for an international trusteeship to be imposed on South Sudan, slamming the two leaders for failing to safeguard the peace. Dr Mask D’Agot, a member of former political detainees group called on President Kiir and Dr Machar to resign.

Advocacy groups such as Amnesty International and Human Rights Watch have called for an arms embargo and additional sanctions, but another NGO focused on South Sudan is urging caution in taking such steps.

“With a fragile ceasefire agreed and thus far holding,” the Brussels-based International Crisis Group declared last week, “any punitive international action should be imposed carefully — and only in close co-ordination with Igad and regional powers. Otherwise it could undermine the ceasefire or even empower hardliners who support renewed war.”

Prof Clemence Pinaud, a South Sudan expert at a US university said that even if the US persuades the Security Council to impose an arms embargo, “it may be too late; the government is already in possession of attack helicopters that have been used to devastating effect.”

It could also be difficult to prevent both the government and rebel forces from acquiring additional weapons in transfers across South Sudan’s porous borders, experts warn.

But an arms embargo would still be seen as “an important symbol” of international determination to stop the killing in South Sudan, Prof Pinaud said, adding that sanctions might prove equally challenging to enforce.

Other researchers surpport that view. While faulting Mr Machar’s armed opposition for violations of the August 2015 peace agreement, Prof de Waal, who is also the head of the World Peace Foundation at Tufts University, said that the forces now under at least nominal command of President Kiir have failed to fulfill historic opportunities for peace and development in South Sudan.

“There is a long and honourable history in Africa of liberation movements holding themselves to higher standards than those of their oppressors,” Prof de Waal notes. “The opposite has been the case” with the South Sudan army and its political wing, he commented in an interview.