Masks will once again be mandatory in situations where people cannot maintain 1.5 metres of distancing starting on Saturday in Iceland, the government decided amid a resurgence of COVID-19.

The announcement reverses an effort that had been under way to reduce coronavirus regulations in the coming weeks.

In October, Iceland's government had been optimistic enough about the virus' spread that it had expected to lift most restrictions by November 18.

In other tightening, starting on Wednesday large gatherings will be limited to 500 people, down from the current rules allowing 2000.

Restaurants that serve alcohol will have to shut at 11pm, two hours earlier than normal.

The new restrictions are set to be in place for four weeks, meaning they would be lifted on December 8.

Everyone aged 16 and older will also be eligible for a booster shot against the coronavirus.

About 160,000 invitations for such shots will be sent by the end of the year, according to a report by broadcaster RUV.

Despite the situation having appeared to have calmed down just weeks ago, Iceland has recently been hitting new daily records in terms of numbers of cases reported.

Croatian authorities will also limit gatherings and widen the use of COVID-19 passes to curb soaring infections after the numbers of infected people hit new records again on Friday.

The country's crisis team said after a meeting that the new rules for gatherings will apply starting on Saturday while the use of COVID-19 passes will take more time to prepare.

Prime Minister Andrej Plenkovic complained that vaccination is going "at snail's pace" after reaching 50 per cent of the population of 4.2 million.

"That is not normal," Plenkovic said, according to the state HRT television.

"We have had a pandemic for nearly two years, more than five million people have died and we have a situation where some of our citizens still do not realise the danger COVID-19 poses."

Like much of central and eastern Europe, Croatia has registered a huge rise in infections and hospitalisations in the past weeks due to low vaccination rates and relaxed virus rules.

Alarmed by the raging virus, some Croats who so far have not gotten vaccinated could be seen lining up on Thursday evening to get a jab at a vaccination point in the capital Zagreb.

Drago Coric said he had been "sceptical" about vaccines but changed his mind after daily new cases peaked to several thousand.

Croatia reported nearly 7000 new infections on Friday after confirming about 6300 a day before.

Japan announced it will ease border controls beginning on Monday for fully vaccinated travellers excluding tourists, responding to requests from the business community following a rapid decline in infections.

Everyone entering Japan must be fully inoculated with COVID-19 vaccines that are recognised by the Japanese authorities.

Those eligible include travellers on short-term business visits of less than three months as well as longer term visitors including foreign students and workers on so-called technical internship programs, with a 14-day quarantine requirement.

Schools and companies sponsoring them are required to submit documents detailing their activities and how they will be monitored.

The 10-day self-isolation for Japanese citizens and foreign citizens with re-entry permits will be shortened to three days.

Japan shut its borders to virtually all foreign visitors in January, except for those with special permits and for humanitarian purposes.

Daily cases have sharply fallen since September, in a trend generally attributed to vaccinations and extensive mask-wearing.

About 73 per cent of the population have been fully vaccinated.

Japan had 158 new confirmed cases on Thursday for an accumulated total since the start of the pandemic of 1.72 million, with about 18,300 deaths.

Deputy Chief Cabinet Secretary Seiji Kihara said Japan is to consider a possibility of allowing foreign tour groups by the end of the year after studying ways to control and monitor their activities.

with AP

Australian Associated Press