New Zealand has extended a strict lockdown in Auckland, requiring 1.7 million people to remain indoors for at least another week to snuff out small outbreaks of the highly infectious Delta variant of coronavirus.

Health authorities recorded 33 new cases of the Delta variant of Covid-19, all in Auckland, which was higher than 23 and 20 cases reported over the weekend.

"It's clear there is no widespread transmission of the virus in Auckland, but so long as we have new cases emerging, there are risks," Prime Minister Jacinda Ardern told a news conference, announcing the decision to prolong the city's lockdown until 21 September.

After that, Auckland will move from level 4 to level 3, which means curbs will be eased slightly but offices, schools and public venues would still stay shut.

New Zealand had been largely virus-free for months until an outbreak of the Delta variant imported from Australia prompted Ms Ardern to order a snap nationwide lockdown on 17 August.

The outbreak has infected 955 so far, most of which have been in Auckland.

The city is virtually cut off from the rest of the country, where the lockdown was lowered last week to level 2, enabling people go back to their offices and schools.

New Zealand's lockdowns and international border closure since March 2020 have been credited with reining in Covid-19, largely freeing up day-to-day activities for people.

There have been just 3,593 cases of Covid-19 in New Zealand since the pandemic began, and 27 related deaths.

But Jacinda Ardern has been criticised for a slow vaccination programme as the country battled the Delta outbreak.

About 34%of its 5.1 million population has been fully vaccinated so far.

New Zealand has purchased Pfizer-BioNTech vaccine doses from Spain and Denmark to boost its inoculation programme.

Vaccinated Sydney residents picnic as lockdown rules relaxed

Virus lockdown rules were relaxed for fully vaccinated people in Sydney today, with small groups allowed to meet for picnics for the first time in months.

Families and friends gathered in parks and at beaches, reuniting 11 weeks after an outbreak of the Delta variant brought Australia's biggest city to a virtual standstill.

The rules remain strict, with just five fully vaccinated people allowed to gather outdoors for up to an hour, while tougher rules are in place for virus hotspots.

Across Sydney, a five-kilometre (three-mile) travel limit remains in place.

Stay-at-home orders are set to be lifted for the fully vaccinated across Sydney and surrounding New South Wales state when the double-dose vaccination rate hits 70% - likely in October based on current trends.

Biden to announce new Covid-19 steps ahead of UN meeting

US President Joe Biden will announce new steps to slow the spread of Covid-19 before the UN General Assembly meets, Surgeon General Dr. Vivek Murthy has said.

Mr Murthy did not specify what the steps would be.

"There will be more actions that we continue to work on, especially in the global front," he said, speaking to CNN on Sunday.

Top health officials believe that Pfizer's Covid-19 vaccine could be authorized for children aged 5-11 years old in the US by the end of October, two sources familiar with the situation have said.

The timeline is based on the expectation that Pfizer, which developed the shot with Germany's BioNTech, will have enough data from clinical trials to seek emergency use authorization (EUA) for that age group from the US Food and Drug Administration (FDA) towards the end of this month, the sources said.

They anticipate the FDA could make a decision on whether the shot is safe and effective in younger children within three weeks of the EUA submission.

Vietnam's biggest city to keep virus curbs

Vietnam's coronavirus outbreak epicentre Ho Chi Minh City will extend its restrictions, state media reported, as the capital Hanoi and several provinces sought an easing of curbs and the aviation authority proposed domestic flights resume.

Ho Chi Minh City authorities said an extension until the end of September was necessary to isolate clusters, speed up inoculations and prevent hospitals being overwhelmed in the city of 9 million people.

Although more than 1 million vaccine shots have been administered daily of late, Vietnam vaccination rate of 5.2% of its 98 million population is one of the region's lowest.

"Overall, Ho Chi Minh City will still be under restrictions for another two weeks," state-run Dan Tri newspaper quoted city vice chairman Duong Anh Duc as saying.

"Although in some districts of the city where the virus is being kept at bay, restaurants are allowed to open for takeaways and people can go out for food."

Vietnam has recorded more than 610,000 infections and 15,000 deaths, the majority of those since May.

Business hub Ho Chi Minh City accounts for half of those infections and 80% of fatalities.