The bid to resolve the near two-year conflict comes as fierce fighting grips northern Ethiopia after a resurgence in combat in August shattered a five-month truce and halted aid into war-torn Tigray.

The AU has invited the warring sides to talks in South Africa that were scheduled to start on Saturday, mediated by the bloc's Horn of Africa envoy Olusegun Obasanjo, South Africa's former deputy president Phumzile Mlambo-Ngcuka and Kenyatta.

AU Commission chair Moussa Faki Mahamat said in a statement on Thursday he had "full confidence in... the distinguished panel members to ensure constructive engagements and dialogue between the parties towards a sustainable, inclusive negotiated settlement to the conflict."

But in a sign of the challenges confronting the process, Kenyatta said in a letter to Faki he would not be attending "due to conflicts in my schedule".

"However, in the interim and as you consider the possibility for another date for the peace talks, I would be grateful to receive further clarity on the structure and modalities of the talks, including but not limited to the rules of engagement for all the interlocuters invited," he wrote.

Both the Ethiopian government and the Tigray People's Liberation Front (TPLF), which have been at war since November 2020, said on Wednesday they were ready to take part in the AU-led negotiations.

But Tigray's regional authorities said they wanted to know what other parties would be involved, what role the international community would play and logistics such as air travel and security for their negotiating team.

"Considering we were not consulted prior to the issuance of this invitation, we need clarification to some of the following issues to establish an auspicious start for the peace talks," said a statement signed by TPLF leader Debretsion Gebremichael.

Representatives of the AU, the Ethiopian government and the TPLF did not respond to AFP's requests for comment following Kenyatta's announcement.