Slovenia, which has been gradually easing strict lockdown measures, on Friday declared that the spread of the virus is now under control and that European Union residents could now enter from Austria, Italy and Hungary.

Germany prepared to open its border with Luxembourg at midnight and to increase the number of crossings open from France, Switzerland and Austria. Travellers will still need to demonstrate a "valid reason" to enter Germany, and there will be spot checks, but the goal is to restore free travel by June 15.

In the US, retail sales tumbled by a record 16.4 per cent from March to April as business shutdowns caused by the coronavirus kept shoppers away from stores. The Commerce Department's report on retail purchases showed a sector that has collapsed so quickly that sales over the past 12 months are down a crippling 21.6 per cent.

The sharpest drops from March to April were at clothiers, electronics stores, furniture stores and restaurants. A long-standing migration of consumers toward online purchases is accelerating.

Elsewhere in the US, the Grand Canyon National Park was scheduled to reopen on Friday to allow visitors in for day trips but not overnight. Some regions in New York were also expected to reopen.

Back in Germany, states agreed to drop a mandatory 14-day quarantine for travellers entering from the EU and several other European countries, including Britain, said Armin Laschet, the governor of the western state of North Rhine-Westphalia.

"Germany will only overcome the corona crisis if European freedom of movement for people, goods and services is fully restored," Laschet said.

Germany has registered more than 170,000 COVID-19 infections and nearly 8000 deaths, but more than 150,000 people have recovered and the country has been recording fewer than 1000 new cases per day.

In northern Europe, Estonia, Latvia and Lithuania removed travel restrictions between the Baltic countries, which Estonian Prime Minister Juri Ratas called "another step toward normal life".

Austria and Switzerland also moved ahead with easing some border restrictions, and Austria reopened all cafes and restaurants.

In Japan, some schools, restaurants and other businesses started to reopen after the country lifted its coronavirus emergency, while keeping in place restrictions in limited urban areas like Tokyo where risks remain.

The head of the World Health Organisation's Europe office, Hans Kluge, warned that distancing guidance and other protective measures were more important than ever.

"It's very important to remind everyone that as long as there is no vaccine and effective treatment, there is no return to normal," he said on French radio Europe-1.

"This virus won't simply disappear, so the personal behaviour of each of us will determine the behaviour of the virus. Governments have done a lot, and now the responsibility is on the people."

Worldwide, there have been more than 4.4 million coronavirus infections reported and 300,000 deaths, while nearly 1.6 million people have recovered according to a tally kept by Johns Hopkins University.

Australian Associated Press