GENEVA, March 5 (Xinhua) -- World Health Organization (WHO) officials said on Friday that the COVID-19 pandemic has caused more "mass trauma" than World War II and warned of its lasting consequences.

"The world has experienced mass trauma because World War Two affected many, many lives," WHO director-general Tedros Adhanom Ghebreyesus said at a virtual press conference.

"And now, even with this COVID pandemic, with bigger magnitude, more lives have been affected, almost the whole world is affected," he said, adding that the pandemic induced mass trauma is "beyond proportion and even bigger than what the world experienced" after the Second World War.

"Countries have to see it as such, and prepare for that," he warned.

Evidence of mass trauma has been presented by other organizations, such as the International Council of Nurses, which warned on Jan. 13 of the effects of the pandemic on nurses' mental health.

Mass trauma could even affect transmissibility, as it would be "very difficult to sustain behaviors that stop the epidemic" for affected communities, said Michael Ryan, executive director of the WHO's Health Emergencies Programme, at the press conference.

"The mental health and psychosocial support to individuals and communities must be central to all recovery plans and must be costed in to those plans," he said.

According to Maria Van Kerkhove, COVID-19 technical lead for the WHO, "there needs to be a lot more emphasis by governments, by communities, by families, by individuals to look after our well-being."