South Sudanese President Salva Kiir is expected to sign a peace deal Wednesday, aimed at ending 20 months of civil war.

At least seven ceasefire deals have been agreed and then shattered within days — if not hours — in the world's newest country, which broke away from Sudan in 2011.

The latest proposed deal, already signed by rebel chief Riek Machar, sets out clear steps towards power sharing, with fixed time frames for implementation.

The deal is backed by the regional eight-nation bloc Igad, the Intergovernmental Authority on Development, as well as the United Nations, the African Union, China, Britain, Norway and the US.

South Sudan's government has expressed "reservations" about the deal, and it remains unclear if Mr Kiir will sign all its clauses.

Here are the key points of the 72-page agreement.

Ceasefire

Fighting must end immediately, with a "permanent ceasefire" beginning 72 hours after the deal is signed.

Troops on either side have 30 days to gather for "separation, assembly and cantonment" — or confinement to barracks, with their weapons kept in storage — with a security review required before an eventual merger of the two forces.

Foreign forces out

All foreign forces embroiled in the war — mostly Ugandan troops backing Mr Kiir — must leave within 45 days.

Foreign militias, including rebels from neighbouring Sudan's Darfur and Nuba mountain regions, must also be disarmed and sent home.
No troops are allowed within a 25-kilometre (15-mile) radius of the capital Juba.

Only presidential guard members, police and guards protecting infrastructure can remain in the city.
Child soldiers and prisoners of war must be released, and free access given to aid workers.

First vice-president

The deal gives rebels the post of "first vice president", alongside the current vice president.

That means Machar would likely regain the post he occupied before being sacked by Mr Kiir in July 2013, six months before the war began.
Signatories also take responsibility for the war, "apologising unconditionally" for the tens of thousands killed in a conflict marked by widespread atrocities on both sides.

Transitional government

A "transitional government of national unity" will take office 90 days after the signing of the deal and govern for 30 months.
Elections must be held 60 days before the end of the transitional government's mandate - meaning that if Mr Kiir signs now, polls would be slated for early 2018.
At a national level, the government gets 53 per cent of ministerial posts and the rebels 33 per cent, with the remaining seats for other parties.
In seven of the 10 states, the government will get 85 per cent of ministerial posts.

But in the battleground states of Jonglei, Unity, and Upper Nile, the government gets 46 per cent and the rebels 40 per cent of posts.
In Unity and Upper Nile states, the main oil regions which have been among the areas hardest hit by the war, the rebels also get to select the powerful post of governor.

War crimes court

A Commission for Truth, Reconciliation and Healing will be set up to investigate "all aspects of human rights violations."

A "hybrid court", set up in collaboration with the African Union, will try crimes, including possible genocide, crimes against humanity and war crimes.
Those indicted cannot be part of the transitional government.

"No one shall be exempted from criminal responsibility on account of their official capacity as a government official, an elected official or claiming the defence of superior orders," the deal says.