(This Oct. 25 story has been corrected to clarify in paragraph 13 the sequence of events that led to the war)
JOHANNESBURG (Reuters) - The first formal peace talks aimed at ending two years of war between the Ethiopian army and forces from the country's northern region of Tigray started in South Africa on Tuesday and will end on Sunday, the South African government said.
At stake is an opportunity to end a conflict that has killed thousands, displaced millions and left hundreds of thousands on the brink of famine in Africa's second most populous nation, destabilising the wider Horn of Africa region.
The talks, mediated by the African Union, begin as the government has been making significant gains on the battlefield, capturing several large towns in Tigray over the past week.
The government offensive, conducted jointly with allied troops from neighbouring Eritrea, has raised fears of further harm to civilians, leading African, U.S. and European leaders and Pope Francis to call for a ceasefire and urgent talks.
The African Union said its chairman, Moussa Faki Mahamat, was "encouraged by the early demonstration of commitment to peace by the parties", without elaborating.
South Africa "hopes the talks will proceed constructively and result in a successful outcome that leads to lasting peace for all the people of our dear sister country Ethiopia," said Vincent Magwenya, spokesperson for President Cyril Ramaphosa.
The African Union mediation team is led by former Nigerian President Olusegun Obasanjo, supported by former Kenyan President Uhuru Kenyatta and former Deputy President of South Africa Phumzile Mlambo-Ngcuka.
United Nations and the United States representatives participated as observers, the African Union said.
"We are looking very eagerly at Pretoria to the talks. That's the only way forward," Filippo Grandi, the United Nations High Commissioner for Refugees, told a press conference on Tuesday evening in Nairobi. "If the parties do not really engage meaningfully in a negotiated solution we'll be in this situation forever."
U.S. Secretary of State Antony Blinken urged the parties to engage seriously and agree an immediate truce.
"These talks represent the most promising way to achieve lasting peace and prosperity for all Ethiopians," he said in a statement.
'MAN MADE FAMINE'
The conflict stems from grievances dating back to the nearly three decades when the Tigray People's Liberation Front (TPLF), a rebel movement-turned-political party, dominated Ethiopia's ruling coalition until 2018.
The party lost power at the national level after falling out with the government led by Prime Minister Abiy Ahmed but continued to dominate its northern stronghold.
The government has accused the TPLF of seeking to restore its national dominance, which it denies, while the TPLF has accused the Abiy government of oppressing Tigrayans and over-centralising power, which it denies.
The Tigrayan delegation has said its focus at the talks in South Africa would be on an immediate cessation of hostilities, unfettered access to Tigray for humanitarian aid, and the withdrawal of Eritrean forces.
The government has said it views the talks as an opportunity to resolve the conflict and "consolidate the improvement of the situation on the ground", apparently a reference to its military advances in Tigray.
The war has compounded other serious problems in Ethiopia including a drought, the worst in four decades, that has caused a food crisis and damaged the economy.
Earlier on Tuesday, World Health Organization head Tedros Adhanom Ghebreyesus, who is from Tigray and served as a minister in the Ethiopian government in the past, issued the latest in a series of public criticisms of the current government's actions.
"Due to the siege in #Tigray, Ethiopia, many people have died of starvation, man made famine & lack of access to essential health care in past 2 years," Tedros wrote on Twitter.
The Ethiopian government has denied allegations from humanitarian organisations that it was blocking them from accessing Tigray. It has accused Tedros of trying to secure arms and diplomatic backing for Tigray forces, which he denies.
(Additional reporting by Hereward Holland and Ayenat Mersie; Writing by Estelle Shirbon; Editing by Bernadette Baum, Jonathan Oatis, Josie Kao and Lincoln Feast.)
