UN Secretary-General António Guterres is gravely concerned about renewed fighting in northern Ethiopia and calls for an immediate cessation of hostilities, his spokesman said on Friday.

"The secretary-general is gravely concerned by the renewed fighting in the Tigray, Afar and Amhara regions of Ethiopia. He calls on all parties to cease hostilities immediately and urges the signatories to return to dialogue under the framework of the Pretoria Agreement," Stephane Dujarric, the spokesman, said in a statement.

"The secretary-general reminds all states in the region of their obligation under the United Nations Charter to refrain from the threat or use of force against the territorial integrity or political independence of any state, and of the principle of non-interference in internal affairs," said the statement.

Guterres also calls on all states with influence on the parties to use it to support de-escalation and refrain from any action that could fuel the conflict, and stands ready to offer his good offices, according to the statement.