(AFP) - East African leaders gathered in Ethiopia on Thursday hoping to revive stalled South Sudan peace talks, following a long-awaited face-to-face meeting between the two warring leaders.

President Salva Kiir and his former deputy turned rebel leader Riek Machar held face-to-face talks on Wednesday, brokered by Ethiopian prime minister Abiy Ahmed, in their first meeting in nearly two years.

What was discussed has been kept under wraps, but video footage of their initial meeting shows Abiy sandwiched between the two towering South Sudanese after cajoling them into an awkward group hug.

The last time Kiir and Machar met was at the outbreak of deadly fighting in the South Sudanese capital Juba in July 2016.

Machar, defeated, then fled to neighbouring Democratic Republic of Congo and then into exile in South Africa where he was placed under de-facto house arrest.

Foreign ministers of an eight-nation bloc called the Intergovernmental Authority on Development (IGAD) met the day after the talks.

They were to be followed by heads of state and government, who are expected to heap pressure to restart the so far fruitless peace talks.

"We need South Sudan to get out of the tragic crisis, stand on its own feet and rejoin the community of nations," Ethiopian Foreign Minister Workneh Gebeyehu said.

The civil war in South Sudan has killed tens of thousands and driven a third of the country's 12 million people from their homes since it began in December 2013, just two year's after Africa's youngest country gained independence.

Analysts warn that the failure of multiple previous rounds of IGAD peace talks, and Kiir and Machar's notoriously volatile relationship and entrenched positions, casts doubt on the likely success of any reconciliation between them.

It is also unclear whether either man has the ability to halt a war that has metastasised, splintered and spread over the more than four years since Kiir accused Machar of plotting a coup.

It was an IGAD agreement in 2015 that eventually brought Machar back to Juba, only for vicious and deadly fighting to break out soon after.

The meeting in Addis Ababa comes against a background of growing international frustration.

In May, the UN Security Council gave the two warring sides a month to reach a peace deal or face sanctions.

© Agence France-Presse