The World Health Organization has urged people to cancel some of their holiday plans to protect public health, as the Omicron variant spreads globally.

“An event cancelled is better than a life cancelled,” said WHO head Dr Tedros Adhanom Ghebreyesus, adding that “difficult decisions” must be made.

Several countries have acted to try to halt the spread of the variant, including imposing travel curbs.

In the US, Omicron is now dominant, accounting for 73% of new infections.

President Joe Biden is expected to address the nation on Tuesday but the White House said he was not planning on “locking the country down”.

The country’s top infectious disease expert, Dr Anthony Fauci earlier warned that Christmas travel would increase the spread of Omicron even among the fully vaccinated.

Americans are now advised against travel to more than 80 nations that appear on the Centers for Disease Control and Prevention’s Very High list for Covid-19, including almost all of Europe.

France and Germany are among the nations imposing travel curbs to tackle Omicron, while the Netherlands has introduced a strict lockdown over the Christmas period.

In the UK, prime minister Boris Johnson said on Monday that the government needed to reserve the possibility of bringing in new rules in England as Omicron cases surged, but did not announce further restrictions.

New Year’s Eve celebrations in London’s Trafalgar Square have been cancelled “in the interests of public safety”, Mayor Sadiq Khan said.

And on Tuesday, New Zealand postponed its phased reopening to international travel until the end of February at least.