Analysts have welcomed peace talks in South Africa between regional leaders of Ethiopia's Tigray region and the federal government but say both sides must get serious this time amid a war that has killed thousands.

UN chief Antonio Guterres warned Monday that the situation in Ethiopia was "spiralling out of control" as fighting raged in the north of the country and the government vowed to seize control of airports and other sites in Tigray.

There has been a sustained diplomatic push trying to bring peace to the Tigray region, with the conflict parties holding talks in neighboring Djibouti. Just days ago, the Tigray People's Liberation Front said it was ready for a ceasefire. But now there is more violence again.

UN chief Antonio Guterres warned Monday that the situation in Ethiopia was "spiralling out of control" as fighting raged in the north of the country and the government vowed to seize control of airports and other sites in Tigray.

Violence and destruction have reached alarming levels," Guterres told reporters at the United Nations. "Hostilities in the Tigray region of Ethiopia must end now," he said, also calling for the "immediate withdrawal and disengagement" of Eritrean forces.

'Situation in Ethiopia is spiraling out of control'

The warring sides in Ethiopia's two-year-long brutal conflict head to South Africa for peace negotiations, although the talks are pushed back to Tuesday. Staying in South Africa, President Cyril Ramaphosa submits his "action plan" in response to the Zondo Commission's report into graft and fraud in the public sector under his predecessor Jacob Zuma.

Peace talks aimed at ending the two-year-old conflict in the Tigray regions of Ethiopia have begun in Pretoria. The negotiations follow a surge in violence in recent weeks.

Every party involved in the war in northern Ethiopia has committed crimes against humanity, Amnesty International said on Wednesday, calling for a probe into abuses in the nearly two-year conflict.

The World Health Organization warned that hospitals are running dangerously low on medical supplies, as fighting between federal and Tigrayan forces intensify following a lull in the conflict between March and August.

The African Union has been mediating an end to the two-year conflict. The deal came hours after Ethiopian Prime Minister Abiy Ahmed claimed his forces were close to "winning".

The Ethiopian government and Tigrayan forces formally signed a truce Wednesday, raising hopes that two years of devastating war that threatened to tear apart Africa’s second-most-populous country might be coming to an end.