Asia-Pacific countries should boost their healthcare capacity and fully vaccinate their people to prepare for a surge in COVID-19 cases fueled by the Omicron variant, officials at the World Health Organization (WHO) said on Friday.

First detected in southern Africa last month and dubbed a "variant of concern" by the WHO, scientists are still gathering data to establish how contagious Omicron is and the severity of the illness it causes.

"Border controls can buy time, but every country and every community must prepare for new surges in cases," Takeshi Kasai, WHO regional director for the western Pacific, told a virtual media briefing.