UNITED NATIONS, Feb. 28 (Xinhua) -- Now is the time for all governments to step up and do everything possible to contain COVID-19 while respecting human rights without stigmatization, UN Secretary-General Antonio Guterres told a press encounter Friday.

"We are seeing cases in a number of new countries, including now also the African continent," he said. "This not a time for panic -- it is time to be prepared -- fully prepared."

"We know containment is possible, but the window of opportunity is narrowing," he said.

The UN chief appealed for solidarity and full global support with all countries fully assuming their responsibilities.

"As they do so, they can count on the support of the United Nations and naturally of the World Health Organization, that is part of our family," he said.

The World Health Organization on Friday raised the risk assessment of COVID-19 from "high" to "very high" at global level.