Pact has more than 110 operation sites in 15 countries around the world, mostly in Australasia and Asia.
It employs more than 6000 people and is the "largest manufacturer of rigid plastic packaging products" in Australasia, according to the company's website.
Associate Environment Minister Eugenie Sage said the money means material that is usually discarded as waste can be recycled and reused locally, rather than sent away overseas.
The move comes as China ramps up its "National Sword" initiative – a strict regulation scheme which aims to limit the amount of waste imported into the country.
Sage said the $3 million spend was an effective response to the new scheme and was a key part of tackling the plastic pollution challenge.
"This new plant will contribute usefully to increasing New Zealand's onshore recycling infrastructure," Sage said.
The $3 million amounts to half of the total cost of a new plant - Pact will cover the rest of the cost.
Sage said that New Zealand's economy to date has been based on a "take, make and dispose" model, which treats nature and the resources it provides as "free" and disposable.
The funding spent on the new plant would help New Zealand shift to a more sustainable and efficient circular economy, where products are designed to have a long life.
Pact's Executive General Manager Eric Kjestrup said the plant will be in Auckland.
When at full capacity, the site will have the ability to process about 10,000 tonnes of recyclable material every year.
"We are absolutely delighted to have received this funding and would like to thank the NZ Government for their support."