Countries should consider recommending that passengers wear masks on long-haul flights, given the rapid spread of the latest omicron subvariant of COVID-19 in the United States, World Health Organization officials said on Tuesday.

In Europe, the XBB.1.5 subvariant was detected in small but growing numbers, WHO and Europe officials said at a news briefing.

Passengers should be advised to wear masks in high-risk settings such as long-haul flights, said the WHO's senior emergency officer for Europe, Catherine Smallwood.