The coronavirus pandemic is accelerating, with Thursday's 150,000 new cases the highest in a single day and nearly half of them in the Americas, the World Health Organization (WHO) said.
"The world is in a new and dangerous phase," Director General Tedros Adhanom Ghebreyesus told a virtual briefing from WHO headquarters in Geneva.
"The virus is still spreading fast, it is still deadly, and most people are still susceptible."
More than 8.53 million people have been reported infected by the novel coronavirus globally and 453,834 have died, a Reuters tally showed as of 1326 GMT on Friday.
Tedros, whose leadership of the WHO has been severely criticised by US President Donald Trump, urged people to maintain social distancing and "extreme vigilance."
As well as the Americas, a large number of new cases were coming from South Asia and the Middle East, Tedros added.
'DRIVEN BY DATA'
With many nations easing restrictions but fearful of a second wave of Covid-19 disease, WHO emergencies expert Mike Ryan urged a gradual and scientific approach.
"Exiting lockdowns must be done carefully, in a step-wise manner, and must be driven by the data," he said.
"There is no specific definition of a second wave," he added, saying new clusters did not necessarily mean a second wave while "second peaks" were also possible in one wave.
Ryan praised Germany, China and South Korea for their handling of the pandemic.
WHO epidemiologist Maria van Kerkhove said easing of lockdowns had to be accompanied with good public health measures. "It is about being able not only to lift these measures carefully but being able to reactivate them," she added.