America's top infectious diseases official has warned that ending lockdowns too quickly could trigger uncontrollable new coronavirus outbreaks, as the global death toll closes in on 300,000.
The stark words from Anthony Fauci came as much of the United States and Europe press ahead with easing curbs that have confined billions to their homes to stem the spread of the disease.
Opening up continues despite the toll spiking in some of the world's most populated countries, with Brazil, Russia and the US all reporting bad news.
Concerns were compounded Tuesday by Fauci's warning to Congress that a run of 14 days with drop in cases was a vital first step before lifting lockdowns.
"If a community or a state or region doesn't go by those guidelines and reopens... the consequences could be really serious," he said.
"There is a real risk that you will trigger an outbreak that you may not be able to control."
Fauci said the true number killed by the epidemic in the US is likely higher than the official toll of over 82,000 -- the world's highest.
On Tuesday the US registered 1,894 coronavirus deaths in 24 hours, a steep rise after daily tolls fell below 1,000 on Sunday and Monday.
The expert's cautionary message stands at odds with rhetoric from President Donald Trump, who has pressed for rapid steps to rekindle the devastated US economy before a November election.
Trump has sought to shift focus onto the role of China, where the virus first emerged in December.
Republican allies in the Senate on Tuesday proposed legislation that would empower the president to impose sanctions on Beijing if it does not give a "full accounting" for the outbreak.
"The Chinese Communist Party must be held accountable for the detrimental role they played in this pandemic," said Senator Jim Inhofe.
"Their outright deception of the origin and spread of the virus cost the world valuable time and lives as it began to spread."
In the House of Representatives meanwhile, Democrats unveiled a $3 trillion virus response package, the largest yet, to fund efforts to fight the pandemic and provide emergency payments to millions of American households.
The lifting of lockdowns gathered pace across Europe on Tuesday, with France beginning to reopen primary schools and nurseries.
Teachers wore face masks and desks were separated as children filed back into classrooms.
Russia began easing lockdown rules even as infections surged past 232,000 -- now the second most cases in the world after the US.
The nation hit the landmark on Tuesday after a week of reporting more than 10,000 daily infections.
President Vladimir Putin's spokesman, Dmitry Peskov, has also tested positive for the virus.
For those braving public transport in Moscow, masks and gloves were a must in line with new anti-virus rules.
"It's a necessary measure," said 25-year-old Tatiana Khan, speaking on a half-empty bus.
"If everyone had worn masks from the start, observed the precautions, I think we wouldn't have had such a spread of the epidemic."
Indian Prime Minister Narendra Modi announced a $270 billion economic stimulus as the Asian giant's economy lumbers back to life after a prolonged shutdown.
Its giant railway network also restarted, despite a recent surge in infections, with 3,600 recorded on Monday.
The country of 1.3 billion imposed a strict lockdown in late March, which Modi's government has credited with keeping cases to a modest 70,000, with around 2,300 deaths.
Fears of a second wave of cases remain across much of the Asian continent, with Chinese state media reporting that the city of Wuhan, where the virus was first detected, plans to conduct virus tests on the entire 11 million population.
The proposal comes after Wuhan reported the first cluster of new infections since the city reopened on April 8 after a 76-day lockdown.
But there were stories of hope amid the gloom. A 113-year-old woman, believed to be the oldest person living in Spain, was reported to have beaten the coronavirus at a retirement home where several other residents died from the disease.
Maria Branyas became infected in April but fought off the illness during weeks of isolation in her room.
Her daughter said her mother was "in shape, wanting to talk, to explain, to reflect -- she has become herself again".