The World Health Organization called Tuesday for countries to keep calm and take "rational” measures in response to the new coronavirus strain Omicron.

"We call on all member states to take rational, proportional risk-reduction measures," WHO chief Tedros Adhanom Ghebreyesus said in a briefing to countries.

With the new, highly-contagious variant of the SARS-CoV-2 virus – Omicron – spreading across the world, several countries have started imposing stricter travel guidelines in order to check the spread of the virus.

But, the World Health Organization on Tuesday warned that blanket travel bans will not prevent the spread of the Omicron strain, despite the global health watchdog classifying it as a 'variant of concern'.

"Blanket travel bans will not prevent the international spread, and they place a heavy burden on lives and livelihoods. 

Additionally, they can adversely impact global health efforts during a pandemic by discouraging countries to report and share epidemiological and sequencing data," the WHO said in its travel advisory statement.

(With input from agencies)