The virus has killed some 6,500 people and infected about 10 million.
The US has reported some 1,500 deaths, while a record-high number of infections has been reported in neighbouring countries including South Africa, the Philippines, Canada, India and China.
The WHO says the pandemic is spreading rapidly in many parts of the world and has already claimed more than 700,000 lives.
“We are in the middle of a pandemic, but it’s far from over,” said WHO Director-General Margaret Chan.
Dr David Mancuso, the World Health Organization’s director of public affairs, told the BBC that while there had been a “substantial increase” in the number of cases in the last few days, the WHO still expected a slow-down in the spread. “
If we want to avoid more deaths, we have to act quickly and decisively.”
Dr David Mancuso, the World Health Organization’s director of public affairs, told the BBC that while there had been a “substantial increase” in the number of cases in the last few days, the WHO still expected a slow-down in the spread.
“This is not the end,” he said.
“It’s just a beginning.
We need to be careful and take stock of what’s happening and what we need to do.”
WHO says it expects the number to climb as more countries report their own data, including China, India, Pakistan and Thailand.
It says more than 100 million people are expected to have been infected by the end of March.
WHO officials said that the global spread of the pandemics virus was unprecedented and that it was a “challenging situation”.
The virus is spread by direct contact with infected blood or tissue and can cause severe disease.
WHO estimates more than one million people in the world died from the virus in 2014.
In some parts of Asia, China and India, it has killed tens of thousands of people.
In the Philippines and South Korea, about one million infections have been reported.
Dr Mancoso said the WHO was working with the government and private sector to help contain the spread of a new coronavirus strain that had not been seen in decades.
WHO says there is no evidence of a global pandemic yet and the WHO is continuing to monitor cases in affected countries and will continue to provide updates as more information becomes available.
WHO’s director-general said the global situation was “very complex” and it was “critical” to do everything possible to limit the spread to minimise the risk of further deaths and economic damage.