Thermo Fisher Scientific Inc said on Monday its COVID-19 diagnostic tests can accurately detect the new coronavirus variant Omicron that has made several countries to shut their borders.

The World Health Organisation (WHO) last week classified the Omicron variant as a SARS-CoV-2 "variant of concern," saying it may spread more quickly than other forms.

Thermo Fisher's TaqPath COVID-19 assays can report accurate results even in the case where one of the gene targets is impacted by a mutation, the company said in a statement.

"This assay can be used not only to successfully detect COVID-19 but_ it also be used as a proxy for the variant," Mark Stevenson, chief operating officer at Thermo Fisher Scientific, said in an interview.

Stevenson said this is the only COVID-19 diagnostic test authorized by the US Food and Drug Administration and currently in use by health systems that can be used to indicate if a case is caused by the Omnicron variant.

Test samples must still be sent to a lab for sequencing to confirm that the case was caused by Omnicron and not another variant with similar features, such as the Alpha variant, he said.

Omicron, which was first detected in Southern Africa, has now been confirmed in Australia, Belgium, Botswana, Britain, Denmark, Germany, Hong Kong, Israel, Italy, the Netherlands, France, South Africa, and the United States' neighbor to the north, Canada.

The WHO said it was working with technical experts to understand the potential impact of the variant on existing countermeasures against COVID-19, including vaccines.