In a letter sent to the UN Secretary-General Antonio Guterres dated Wednesday, the leader of the Tigray People's Liberation Front, Debretsion Gebremichael, called for a conditional cessation of hostilities as fighting escalates on multiple fronts.
According to a copy of the letter seen by AFP and confirmed by TPLF spokesman Getachew Reda, Debretsion said the truce would depend on four conditions, including "unfettered humanitarian access" and the restoration of essential services in Tigray.
The resumption of fighting last month shattered a March truce, with frantic diplomatic efforts now under way to find a peaceful resolution to the nearly two-year war.
The truce had allowed aid convoys to travel to Tigray for the first time since mid-December but on Wednesday, a UN report said deliveries, including by air, had been halted due to renewed fighting.
The violence has also hit access to aid in the neighboring Amhara region.
Ethiopia's northernmost region has suffered severe food shortages and limited access to basic services including electricity, communications and banking.
Fighting erupted around Tigray's southeastern border on August 24, but has since spread along the region's southern border to areas west and north of the initial clashes.
A diplomatic source and a foreign source told AFP on Thursday that fighting had intensified along Tigray's northern border, with pro-government forces and troops from neighboring Eritrea -- which backed Ethiopia's army in the early stages of the war -- targeting rebel positions.
AFP was not able to independently verify the claims. Access to northern Ethiopia is severely restricted and Tigray has been under a communications blackout for over a year.
Debretsion also called for "the withdrawal of Eritrean forces from every part of Ethiopian and Tigrayan territory, under international monitoring, to positions in which they can no longer pose any threat to us".
He also asked the Security Council to ensure the withdrawal of troops from western Tigray, a disputed region claimed by Amharas and Tigrayans, that has been occupied by Amhara forces since the war erupted, triggering large-scale displacement and US warnings of ethnic cleansing.
There was no response from the Ethiopian government to the letter.
The uptick in violence has sparked international concern, with the US envoy to the Horn of Africa, Mike Hammer, extending his stay in Ethiopia, according to diplomatic sources.
The warring sides have traded blame for starting the latest round of hostilities.
The war erupted in November 2020 when Prime Minister Abiy Ahmed sent troops to topple the TPLF, the region's former ruling party, saying the move came in response to attacks by the group on army camps.