Prime Minister Scott Morrison has hailed the opening up of the Australia-New Zealand travel bubble as a "win-win" for both countries.
Travellers from Australia are once again able to cross the Tasman quarantine-free after more than a year of tight border restrictions, with the first flight out of Sydney due to take off around 6am.
"Today's milestone is a win-win for Australians and New Zealanders, boosting our economies while keeping our people safe and just in time for Anzac Day," Mr Morrison said in a statement on Monday.
"Both countries have done a remarkable job in protecting our communities from COVID and two-way flights are an important step in our road out."
New Zealand Prime Minister Jacinda Ardern was equally delighted at the re-opening of borders.
"It is truly exciting to start quarantine-free travel with Australia," Ms Ardern said in a joint statement with Mr Morrison.
"Be it returning family, friends or holidaymakers, New Zealand says welcome and enjoy yourself.
"The bubble marks a significant step in both countries' reconnection with the world and it's one we should all take a moment to be very proud of."
All people residing in Australia or New Zealand, including foreign nationals, can use quarantine-free travel, as long as they meet the health, immigration and other standard border clearance requirements in each country.
The easing of the border restriction reciprocates the arrangement already in place for Kiwi arrivals, who have been able to visit Australia without undertaking quarantine for about the last six months.
While the Australia-New Zealand bubble was "the first cab off the rank", it's hoped more travel bubbles will soon follow.
Ms Ardern and Mr Morrison said travel to Pacific nations could be next as Australia and New Zealand explore opportunities to extend quarantine-free travel to those countries "when it is safe to do so".
However, those travelling between Australia and New Zealand need to be prepared for their plans to be disrupted at short notice if a coronavirus outbreak emerges.
Australian Associated Press