"The allegations [by NGO Human Rights Watch] are not substantiated by evidence," Ethiopia's Government Communication Service (GCS) said in a statement.
"This distorted and misleading portrayal of the situation attempts to undermine peaceful co-existence and fuel inter-ethnic conflict and obstruct the national efforts for peace and reconciliation."
HRW said in a report issued on June 1 that the November peace agreement to end the two-year conflict in Tigray had not stopped "ethnic cleansing" in the disputed western part of the region.
"Since the outbreak of armed conflict in Tigray in November 2020, Amhara security forces and interim authorities have carried out a campaign of ethnic cleansing against the Tigrayan population in Western Tigray, committing war crimes and crimes against humanity," HRW said.
Western Tigray - land under Tigray's authority but also claimed by Amharas as ancestrally theirs - was swiftly captured by federal and Amhara forces during the war.
A concerted campaign of "forced expulsions" began in earnest and did not let up despite the November deal, HRW said.
But the Ethiopian government said the U.S.-based rights group had made the allegations "without conducting a thorough and credible investigation in all areas affected by the conflict."
The GCS statement said the government had embarked on nationwide consultations on a process for transitional justice which would allow a "comprehensive investigation."
"The truth will be told and perpetrators of crimes will be held accountable," it said.
The U.N.-backed Commission of Human Rights Experts on Ethiopia in September, 2022, issued a report saying there was evidence of widespread human rights violations by all sides during the fighting that erupted in the northern Tigray region in November 2020.