Europe hit more than three million coronavirus cases on Thursday, while spiking infection numbers from Belgium to Tokyo and Melbourne led authorities to reimpose restrictions on citizens.

While EU lawmakers combed through a huge aid package for their economies, the UN called for a basic income for the world's poorest to help slow the spread of the pandemic, and the Red Cross warned of "massive" new migration caused by the economic devastation.

The European continent now accounts for a fifth of the world's more than 15 million cases and remains the hardest hit in terms of deaths, with 206,633 out of 627,307 worldwide.

A 750-billion-euro post-coronavirus recovery plan was hammered out at an EU summit this week, where fiscally-rigid nations butted heads with hard-hit countries like Spain and Italy that have called for huge aid grants.

EU chief Charles Michel said the total stimulus would eventually reach 1.8 trillion euros ($2.2 trillion).

"This moment, it's my conviction, is pivotal in European history. We acted fast and with urgency," Michel told the bloc's parliament in Brussels.

"Europe's response is greater than that of the United States or China," he said.

Meanwhile, the UN warned that the world's poorest also need help.

Funding of $199 billion per month would provide 2.7 billion people with a temporary basic income and the "means to buy food and pay for health and education expenses", the UN Development Programme said.

"Bailouts and recovery plans cannot only focus on big markets and big business," said UNDP administrator Achim Steiner.

UN projections have warned the virus could kill 1.67 million people in 30 low-income countries.

The knock-on effects will also be huge, warned Red Cross chief Jagan Chapagain.

"Many people who are losing livelihoods, once the borders start opening, will feel compelled to move," he told AFP.

"We should not be surprised if there is a massive impact on migration in the coming months and years."

Plateaus and fresh spikes

By far the worst-hit country in the world with close to four million cases and more than 143,000 deaths, the United States reported some stabilisation of its outbreak.

New cases appear to be plateauing in hotspots like Arizona and Florida, even if officials warn that current levels would continue to strain hospitals.

But as the Americas continue to be ravaged by the pandemic, Bolivia announced it was delaying its general election by six weeks to October.

Elsewhere, there were signs that the virus can quickly re-emerge when lockdown measures are lifted.

Australia, Belgium, Hong Kong and the Japanese capital Tokyo all had early successes in containing outbreaks, but are now facing an upsurge, prompting new restrictions.

Anyone venturing out in Australia's second-biggest city Melbourne will have to wear a mask. The same will be true in Belgium's outdoor markets and busy areas from Saturday.

"These measures are not advice, they are orders," Belgian Prime Minister Sophie Wilmes said.

"Announcing a strengthening of the rules is a hard blow for our morale, but we'd prefer to take these measures today than to regret it tomorrow."

South Africa's Medical Research Council has reported a 60-percent increase in overall numbers of natural deaths in recent weeks, suggesting a much higher toll of coronavirus-related fatalities in Africa's worst-hit nation.

'Untrue, unacceptable'

The politics around the virus continued, with WHO chief Tedros Adhanom Ghebreyesus rejecting an allegation by US Secretary of State Mike Pompeo that he owed his position to a deal with China.

Tedros said the claim was "untrue and unacceptable" and warned against the "politicisation of the pandemic".

Meanwhile in France, while the number of foreign tourists in Paris, the world's most visited city, has dwindled during a two-month lockdown, there has been a noticeable increase in home-grown visitors.

"Most clients are clearly French, with lots of families," said a spokesman for catering firm Sodexo, adding that the chic Jules Verne restaurant on the Eiffel tower was booked solid every night in July.

There was also good news for basketball fans in China, who will be allowed back into stadiums from Sunday.

The Chinese Basketball Association on June 20 became the first league to return to action in China following a nearly five-month stoppage.