South Sudan's rivals, Kiir and Machar to meet Monday

Juba-South Sudan's President Salva Kiir and arch-rival Riek Machar, his sacked vice-president, have spent the past 20 months locked in combat.

Civil war erupted in December 2013 after Kiir accused troops loyal to Machar of staging a failed coup.

Both are former rebel leaders who rose to power during Sudan's 1983-2005 civil war between north and south, after which South Sudan seceded in 2011 to form the world's youngest country.

The two leaders come from the south's two main ethnic groups, Kiir from the Dinka people and Machar from the Nuer, tribes that are themselves split into multiple and sometimes rival clans.

They fought both alongside and against each other during the long and bitter war with Khartoum.

The rivals are due to meet at talks on Monday, amid the threat of international sanctions should they fail to strike a deal.

Here are short profiles of the two leaders.

The cowboy-hat wearing ex-guerrilla commander was for years more accustomed to leading troops in bush war than making political speeches, and reluctantly took power only after the death of his chief, South Sudan's first President John Garang, in a 2005 helicopter crash.

But while Kiir led the world's youngest nation as it broke free peacefully from former enemies in Khartoum in July 2011, he has struggled to stem corruption and rebuild after decades of conflict.

Billions from oil revenues have been squandered under Kiir's watch, with the president in 2012 writing a desperate letter to 75 past and present officials begging for the return of an estimated $4 billion in stolen funds.

Born in 1951 in the remote cattle-herding state of Warrap to the majority Dinka people, Kiir spent much of his life carrying a gun, and still sports the thick beard of the bush rebel.

A career soldier, he fought in both Sudan's first civil war, lasting from soon after independence from Britain in 1956 to 1972, as well as the subsequent 1983-2005 conflict.

A devout Roman Catholic, Kiir has often given sermons at the cathedral in Juba, towering down from the pulpit wearing his trademark cowboy hat, a gift from US President George Bush, a key figure in the 2005 peace deal.

He was elected as South Sudan's president in 2011. Elections due in 2015 were delayed due to war.

Charismatic and controversial, Riek Machar once charmed many in the international community with his broad, gap-toothed smile and eloquent speeches, while remaining deeply distrusted by many in South Sudan.

Born in 1953 in the oil-producing state of Unity, Machar comes from the Nuer people.

Machar never underwent the traditional deep horizontal forehead scarring that differentiates Nuer men from boys and has used education as a step up in life.

After an engineering degree in the Sudanese capital Khartoum, he gained his doctorate from Britain's Bradford university.

But he returned to fight after the outbreak of civil war in 1983, winning the support of many of his fellow Nuer to bolster the rebel force, until then dominated largely by Dinka forces.

During the war, Machar took a second wife, British aid worker Emma McCune. Their love story was told in the book "Emma's War" by journalist Deborah Scroggins, a tale once touted in Hollywood as possible film material.

McCune died in a road crash in the Kenyan capital Nairobi in 1993.

Machar grew frustrated with rebel commander John Garang, staging a failed 1991 coup against him and other commanders, including Kiir.

As the rebel army split along ethnic lines, Machar was accused of carrying out a brutal massacre in the Dinka-dominated town of Bor. After forging a breakaway faction, he later signed a deal with his former enemies in Khartoum.

But he returned to the rebel fold in 2002, and after a peace deal was struck in 2005 rose to become vice-president.

Machar sought to rebuild his damaged reputation during the war by leading failed efforts to persuade Uganda's Lord's Resistance Army (LRA) rebels to end their decades-long insurgency.

But he was sacked in July 2013 and, days before the war began, openly challenged Kiir, calling him "dictatorial".

He has since said there can be no peace unless Kiir steps down from power. However, key rebel commanders have split from Machar, weakening his force on the ground.

- AFP