Madrid: More than 40,000 people have been killed in the coronavirus pandemic as the disease barrels across the globe, with the US bracing for its darkest hours after its death toll surpassed China's on Tuesday.

In a matter of months, the virus has infected more than 800,000 people in a crisis redrawing political powers, hammering the global economy and transforming the daily existence of some 3.6 billion people who have been asked to stay home under lockdowns.

Deaths shot up again across Europe Tuesday as Spain, France and Britain reported their deadliest days.

While there are hopeful signs that the spread of infections is slowing in hardest-hit Italy and Spain, more than 800 died overnight in both countries.

With hospitals direly overstretched, lockdowns have been extended despite their crushing economic impact on the poorest.

In Belgium a 12-year-old girl infected with the virus passed away in another worrying case of a youth succumbing to the disease.

Meanwhile the US -- which has the highest number of confirmed infections -- reached a bleak milestone as deaths topped 3,400, ticking past China's official tally of 3,309, according to a Johns Hopkins University tracker.

France joined it with a surge to 3,525 deaths, an official toll that includes only those who died in hospital and not those who died at home or in old people's homes.

The inundation of patients has sent health facilities around the world into overdrive.

Field hospitals are popping up in event spaces while distressed medical staff make grim decisions about how to distribute limited protective gear, beds and life-saving respirators.

In scenes previously unimaginable in peacetime, around a dozen white tents were erected to serve as a field hospital in New York's Central Park.

"You see movies like 'Contagion' and you think it's so far from the truth, it will never happen. So to see it actually happening here is very surreal," 57-year-old passerby Joanne Dunbar told AFP.

While many companies and schools around the globe have shifted to teleworking and teaching over video platforms, huge swaths of the world's workforce cannot perform their jobs online and are now lacking pay and face a deeply uncertain future.

Food banks in New York City, the epicentre of the US outbreak, have seen a surge of newcomers struggling to feed their families.

"It is my first time," Lina Alba, who lost her job as a cleaner in a Manhattan hotel that closed two weeks ago, said from a food distribution centre in the city.

"We need the help now. This is crazy. So we don't know what's going to happen in a few weeks," added the 40-year-old single mother of five.

With more than 175,000 infections in the United States, three-quarters of Americans are now under some form of lockdown.

Off the coast of Florida, a coronavirus-stricken cruise ship and its sister vessel are pleading for somewhere to dock, possibly at Fort Lauderdale.

"Already four guests have passed away and I fear other lives are at risk," Orlando Ashford, president of Holland America Line, wrote in the South Florida Sun Sentinel.

The staggering economic and political upheaval spurred by the virus is opening new fronts for both cooperation and conflict.

In virtual talks Tuesday, finance ministers and central bankers from the world's 20 major economies pledged to address the debt burden of low-income countries and deliver aid to emerging markets.

Last week G20 leaders said they were injecting $5 trillion into the global economy to head off a feared deep recession.

In the European Union, however, battle lines have been drawn over the terms of a rescue plan to finance the expected severe economic fallout.

Worst-hit Italy and Spain are leading a group pushing for a shared debt instrument -- dubbed "coronabonds".

But talk of common debt is a red line for Germany and other northern countries long opposed to such a measure, threatening to divide the bloc in the midst of a health catastrophe.

European Commission chief Ursula von der Leyen warned governments not to use emergency measures as a pretext for power grabs.

Her call followed concerns about a new law that gave Hungary's nationalist leader Viktor Orban sweeping authority to rule by decree until his government deems the emergency is over.

Activists around the world have voiced fears that autocrats will overreach and hold on to their new powers even after the crisis abates.

Elsewhere Poland toughened restrictions on movement while Russia expanded lockdowns across its territory as infections ticked up, including that of the head of Moscow's main coronavirus hospital.

Though the doctor recently met with President Vladmir Putin, the Kremlin insisted the Russian leader is fine.

The economic pain of lockdowns is especially acute in the developing world.

In Tunisia several hundred protested a week-old lockdown that has disproportionately impacted the poor.

"Nevermind coronavirus, we're going to die anyway! Let us work!" shouted one protester in the demonstration on the outskirts of the capital Tunis.

Africa's biggest city Lagos has also been brought to a halt as it entered its first full day of a two-week shutdown.

Containment will be especially tough in the megacity's packed slums, where many rely on daily wages to survive.

"To reduce the number of people with coronavirus, we know they need to stop movement," said 60-year-old engineer Ogun Nubi Victor.

"But there is no money for the citizens, people are just sitting at home, with nothing to eat." While much of the world shuts down, the ground-zero Chinese city of Wuhan has started to reawaken in recent days, giving the bereaved the first chance in months to bury their dead.