Emotions ran high Monday as excited passengers set off on the first flights to take advantage of a quarantine-free travel bubble between Australia and New Zealand, allowing families split when borders closed almost 400 days ago to finally reunite.

"(I'll) yell, scream, cry, hug, kiss, (feel) happy -- all of these emotions at once," Denise O'Donoghue, 63, told AFP at Sydney airport as she prepared to board her flight.

The arrangement means that for the first time since the pandemic closed borders worldwide, passengers can fly in either direction across the Tasman Sea without undergoing mandatory Covid-19 quarantine when they arrive.

"It's a very big day and exciting for families and friends," said New Zealand Prime Minister Jacinda Ardern, who hailed the success of both countries in containing the virus as a key factor in allowing the travel corridor.

Australia was New Zealand's largest source of international tourists before the pandemic, accounting for about 1.5 million arrivals or 40 percent of total visitors in 2019.

But on the first day of the bubble, most of the travelers were returning New Zealanders, with tourists expected to start arriving in large numbers during the upcoming Australian school holidays.

The bubble's opening received saturation coverage from media in both countries, with live television reporting from airports providing regular updates on the progress of flights.

On a grass embankment at the foot of Wellington Airport's runway, the words 'WELCOME WHANAU' (family) were spelled out in giant letters.

In the airport terminal, Maori dancers performed a traditional powhiri welcoming ceremony for the arrivals.

Lorraine Wratt, a New Zealander stranded by the pandemic while visiting family in Australia, told AFP it was "wonderful" to be able to travel again.

"We're very excited to be heading back home but we're gonna miss our family (in Australia) big time," she said. "We came to Australia on December 11 to spend Christmas with our children... planning to go back in February, it's been a bit of a nightmare."

'Back to normal'

Australia is home to hundreds of thousands of expatriate New Zealanders and before coronavirus many regularly shuttled back and forth across the Tasman on three-hour flights.

"It's like it's one big country, so it's very good to open the borders, it will help all the families," Mehat El Masri told AFP as he waited to see his Sydney-based son Shady for the first time in 16 months.

"We appreciate it. We're doing very well in New Zealand and Australia with precautions and keeping things under control... we're fortunate compared to the rest of the world."

O'Donoghue said the travel bubble's opening made her feel the world was returning to some sort of normality.

"I'll be going back, they'll be coming over, we'll just be back to normal," she said.

"What normal's going to be from now on I don't know, but I'm just really, really excited today."

Air New Zealand executive Craig Suckling said the atmosphere at Sydney airport before departure was electric.

"It was quite the emotional rollercoaster here in Sydney," he said. "The check-in area was a hive of activity and at the boarding gate, customers were eager to get on."

The airline's chief executive Greg Foran said it was also a "monumental" day for those involved in the hard-hit tourism industry.

"(It's) a real turning point for the airline. It's day one of our revival," he said.

Australia has previously flagged the possibility of travel bubbles with Singapore, South Korea, Japan and Taiwan, while New Zealand is working to allow unrestricted access to small Pacific states such as the Cook Islands and Tuvalu.

Morrison has also raised the prospect that by year's end, Australians who have received a Covid-19 vaccination may be able to travel internationally then self isolate at home upon return, rather than facing two weeks quarantine in a hotel.

But the leaders of both countries warned further border changes in the wake of the trans-Tasman bubble would be a slow, carefully planned process.

"The idea that on one day everything just opens, that's not how this is going to happen," Morrison said.

"It will happen cautiously and carefully, working very hard on the medical and health protections."