A man walks on the deserted square in front of the Eiffel Tower on March 21, 2020 -- worldwide, almost one billion people have been asked to stay at home to curb the spread of the novel coronavirus. (Photo: AFP)

Almost one billion people were confined to their homes worldwide Saturday as the global coronavirus death toll shot past 11,000 and US states rolled out stay-at-home measures already imposed across swathes of Europe.

The fast-spreading pandemic has completely upended lives across the planet, restricting movement, shutting schools and forcing millions to work from home.

Around 30 percent of Americans were adjusting to life in various phases of virtual lockdown -- including in the US's three biggest cities of New York, Los Angeles and Chicago -- and more states were expected to ramp up restrictions.

The virus death toll crossed 11,000 worldwide, with more than 4,000 alone in worst-hit Italy, while Spain reported a 32 percent spike in new deaths.

An estimated 900 million people are now confined to their homes in 35 countries around the world -- including 600 million hemmed in by obligatory government lockdo

While the elderly and those with pre-existing medical conditions are the hardest hit by the virus, the World Health Organization has warned that young people are also vulnerable.Accurate figures are difficult to come by, however, as many of those who die suffer from other illnesses, and infection rates are uncertain because of a lack of testing in many countries.