World powers are on a war footing against the spiralling coronavirus pandemic.

Italy extended its lockdown after suffering the world`s highest single-day death toll while Europe and the United States unleashed nearly a trillion dollars to prop up the teetering global economy. Across the planet, the death toll has risen to over 9,000 with more than 217,000 infections reported, according to a tally based on official sources.

As countries tried to stem the mounting crisis, Australia and New Zealand moved to seal off their borders with unprecedented entry bans aimed at halting the march of COVID-19.

China marked a major milestone by listing no new domestic infections for the first time since the outbreak first erupted in the central city of Wuhan in December, although a spike in imported cases threatened its progress.

It appeared to have staunched the virus with strict measures including a complete quarantine of Wuhan since January, meaning the number of infections and deaths in the rest of the world have surpassed those in China. But elsewhere the pandemic was worsening quickly, with over 4,100 deaths in Europe exceeding the 3,400 fatalities in Asia. Dire news came out of Italy on Wednesday which reported 475 new deaths, the highest single-day toll of any country, despite having imposed a national shutdown on March 12 that has been copied around the world.

Prime Minister Giuseppe Conte said the lockdown would be prolonged, shattering hopes that Italy`s methods might herald a quick end to the crisis. `We will not be able to return immediately to life as it was before,` he said. Italy has recorded about one-third of global deaths, while badly hit Iran also announced 149 new fatalities, raising its toll to 1,284.

France also mooted extending its own two-week lockdown as the interior minister blasted `idiots` who flout home confinement rules and put others at risk.

With countries paralysed by the pandemic and stock markets imploding, policymakers this week unleashed a wave of measures to shore up the global economy. The European Central Bank announced a 750-billion-euro bond-buying scheme dubbed the `big bazooka`, days after it unveiled a big-bank stimulus package that failed to calm anxious markets.

US President Donald Trump signed a $100 billion emergency aid package to provide free coronavirus testing for those who need it, sick pay and paid family leave.

European stocks staged an early rebound on the stimulus news, although Asian markets took another beating. But the sense of impending doom continues to cast a pall over the world economy with airlines, carmakers and others all warning of bleak times ahead.

`I view (myself) as a, in a sense, a wartime president. I mean, that`s what we`re fighting,` Trump said on as he announced the deployment of military hospital ships to treat a fast-growing number of American patients.

German Chancellor Angela Merkel took a similar tone, saying in an unprecedented televised address: `Not since the Second World War has our country faced a challenge that depends so much on our collective solidarity.` Coronavirus cases in Germany soared past 10,000 with over 2,800 new infections reported in a single day.

Highlighting how the battle is only just beginning in the rest of the world, Russia reported its first death and sub-Saharan Africa also saw its first fatalities, while even the Pacific nation of Fiji said it had its first case.

World Health Organisation head Tedros Adhanom Ghebreyesus urged countries to `come together as one against a common enemy: an enemy against humanity`. He also warned Africa to `wake up` and prepare for the worst.