Prime Minister Scott Morrison on Wednesday announced urgent support for Australia's northern neighbours.
The federal government will also request one million doses ordered from Europe for Australian use be redirected to PNG.
"They're our family. They're our friends. They're our neighbours. They're our partners," Mr Morrison told reporters in Canberra.
"They have always stood with us and we will always stand with them."
The initial 8000 jabs will come from the Australian-manufactured AstraZeneca vaccines, which are expected to be ready from next week.
Mr Morrison is urging European nations to allow one million doses to be exported for use in PNG after Italy blocked a shipment bound for Australia earlier in the month.
"I expect and would hope to get the cooperation out of Europe for this," he said.
The prime minister doesn't believe Australians will criticise the government for providing vaccines to another country.
"When we're talking about our own home, which PNG is part of, our own family, our Pacific neighbours, I think Australians understand that this is one of our responsibilities."
The government is also taking steps to stop the virus escaping PNG into Australia with only a short boat trip separating the two nations. Passenger flights from PNG to Cairns will be suspended from midnight on Wednesday for a fortnight.
All charter flights will be suspended with limited exemptions for freight, medical evacuations and other critical trips.
Passenger caps will be reduced by one quarter on flights from PNG to Brisbane, while fly-in-fly-out (FIFO) journeys will also be suspended.
"You FI or you FO," Mr Morrison said.
Australia will also provide one million surgical masks and 200,000 extra-protective masks.
Around 100,000 gowns and the same number of goggles and bottles of sanitiser will be sent, along with 20,000 face shields and 200 ventilators.
With PNG just kilometres by sea from the Torres Strait Islands, there are grave concerns as case numbers balloon even with low testing rates.
PNG Prime Minister James Marape fears the country's infection rate could be as high as one in every three or four people.
"The number is quite staggering," Mr Marape told reporters in Port Moresby.
"If we don't do a corrective response to this, our health system will be clogged and we won't be able to sustain it."
PNG has recorded 2269 cases of coronavirus since the pandemic began, with almost 100 new cases in the last 24-hour reporting period.
There have been 26 confirmed deaths.