"No, we are not bombarding the city. Our forces are approaching the city of Mekele and are focused on the TPLF junta, not the city", the diplomat said, adding that the Ethiopian military encircled Mekele and the operation was ongoing.
The ambassador said last week that Addis Abeba was in control of the situation and aimed to end the conflict soon.
Earlier in the day, TPLF Chairman Debretsion Gebremichael told Reuters that Mekele was under "heavy bombardment".
The armed conflict, which was fueled by political tensions between the government and the TPLF, started in early November after Addis Abeba accused the Tigray forces of conducting an attack on a military base in the region. The clashes forced tens of thousands of Ethiopians to flee to neighbouring Sudan.