It comes after stricter border controls and harsher quarantine rules are being introduced across the globe in response to the new variant.
New advice issued today has said that travellers must “remain vigilant” while scientific research is underway to understand how the variant behaves.
The advice from the WHO reads: “All travellers should be reminded to remain vigilant for signs and symptoms of COVID-19, to get vaccinated when it is their turn and to adhere to public health and social measures at all times and regardless of vaccination status, including by using masks appropriately, respecting physical distancing, following good respiratory etiquette and avoiding crowded and poorly ventilated spaces.
“Persons who are unwell or at risk of developing severe COVID-19 disease and dying, including people 60 years of age or older or those with comorbidities (e.g. heart disease, cancer and diabetes), should be advised to postpone travel.”
The WHO have also warned that blanket travel bans will not prevent the international spread of the new omicron variant.
It comes after a number of countries, including the UK, EU and US are among t imposed travel bans on South Africa and other parts of Africa.
Currently, passengers arriving in the UK from 4am on Tuesday will be required to take a PCR test by the end of their second day from entry and isolate until they receive a negative test, while 10 southern African nations have been added to the red travel list.
The advice from the WHO reads: “Blanket travel bans will not prevent the international spread, and they place a heavy burden on lives and livelihoods. In addition, they can adversely impact global health efforts during a pandemic by disincentivizing countries to report and share epidemiological and sequencing data.
“All countries should ensure that the measures are regularly reviewed and updated when new evidence becomes available on the epidemiological and clinical characteristics of Omicron or any other VOC.”
It comes as the Health Secretary Sajid Javid said it was not known whether the most recent Omicron cases identified in the UK were linked to travel in South Africa.
He told a press conference: “The cases that we identified at the start of the weekend, we were able to confirm quickly that they were linked to travel to South Africa. They were also part of one sort of family cluster.
“The recent cases that we’ve confirmed today, we’re not able to say whether or not, at this point ... we don’t know, we’re doing that work right now at speed to determine whether they all have a link to South Africa or not.
“Is there likely to be community transmission? I think we have to be realistic, there is likely to be, as we’re seeing in other European countries.
“And also, as I said earlier ... we would expect cases to rise as we now actively look for cases, because now having identified the variant and our concerns around it, UKHSA is actively looking back at anyone who’s travelled to South Africa over the last 10 days or so, and searching for these cases and taking action of course if they find them.”
Meanwhile, Eight more cases of the omicron variant of have been confirmed in England according the UK Health Security Agency (UKHSA).
The total number of cases involving the variant in England so far is 13.