At a news conference in Geneva, World Health Organization Director Tedros Ghebreyesus said the new coronavirus was ten times more deadly than the swine flu, also known as H1N1, which caused a global pandemic in 2009.
"We know that COVID-19 is spreading rapidly, and we know that it is deadly," said Ghebreyesus.
He said it would take a long time to stop the virus because it is slowing down at a low pace.
According to WHO, it will take about 12-18 months to develop a new coronavirus vaccine.