Nigeria on Monday criticised Britain's decision to add the country to a travel "red list" due to coronavirus concerns as unjust and not driven by science.
Nigeria joined South Africa and nine other Southern African countries on the list as of 04:00 on Monday after the British health ministry said most of its cases of the new Omicron variant had clear links to overseas travel from Nigeria and South Africa.
The addition means only UK citizens and residents traveling from Nigeria are allowed entry to Britain and they must quarantine for 10 days in a hotel upon arrival.
"The decision by the British government to put Nigeria on the red list, just because of less than two dozen cases of Omicron...is unjust, unfair, punitive, indefensible and discriminatory. The decision is also not driven by science," Information Minister Lai Mohammed said.
The move was "a knee-jerk reaction" that would be detrimental to efforts to fight the pandemic, he said. Western countries should focus on aiding vaccine access in Africa rather than closing their borders, he said.
First reported in southern Africa, the Omicron variant has highlighted the vaccination gap between rich nations the developing world. Nigeria last week confirmed its first Omicron cases.
Canada and Hong Kong also barred non-resident travelers from Nigeria due to concerns over the Omicron variant, while South Korea said it detected the Omicron variant in fully vaccinated travellers who arrived from Nigeria.