Addis Ababa says the US and its allies are "perpetuating a destructive narrative", rejecting reports that authorities were unlawfully detaining citizens on ethnic grounds.
Ethiopia has said the international criticism that it is arresting citizens based on their ethnicity is incorrect and undermines the African country's sovereignty.
"Insinuating in that regard is misguided, it's not only misguided but it's also perpetuating a destructive narrative," the prime minister's spokesperson Billene Seyoum said on Tuesday, adding that the detentions were "based on credible evidence and testimony".
"This is a legitimate government...going through the constitutional process of enacting any kind of measures for security to ensure that state order is well protected."
She was responding to a statement issued on Monday by the United States, Britain, Canada, Australia, Denmark, and the Netherlands, voicing concern that reports of widespread arrests of ethnic Tigrayans citizens – including women, children, and the elderly – could violate international law.
On November 17, the state-appointed Ethiopian Human Rights Commission said that thousands of people had been arrested since the state of emergency was declared.
Billene said the number of people detained was currently unclear as authorities were conducting investigations and releasing some people.
Abiy says 'enemy will be destroyed'
War broke out in the northern region of Tigray a year ago and has since seeped into two other regions of Ethiopia.
Last month rebels of the Tigray People's Liberation Front and their allies advanced to within 220 kilometres of the capital, but they have since retreated and the government has regained significant territory.
Meanwhile, Prime Minister Abiy Ahmed said in footage aired late on Monday on state media that most of the areas that had been seized by Tigrayan rebels in the Amhara and Afar regions had been retaken by government forces.
"We will continue with (liberating) the remaining areas," he said in a speech to soldiers.
"The victory will continue and nothing will stop us. The enemy will be destroyed."