New Zealand's population is on track to reach 5 million by 2020 - or sooner, Statistics New Zealand says.
The agency said in the 12 months to June, the population has grown at its fastest rate since the early 1960s.
That was a 2.1 percent - or 97,000 - population increase.
"Our population was estimated to be 4.69 million at 30 June 2016, with net migration being 69,100 over the June year," Statistics NZ senior demographer Kim Dunstan said.
The latest projections showed a high chance of the population rising to between 4.9 and 5.1 million by 2020, he said.
By 2025 the population was expected to be between 5 and 5.5 million.
By 2068, the projections were for 5.3 to 7.9 million people.
Much of this was due to net migration running strongly in New Zealand's favour.
Statistics NZ said if there was no migration, the population would peak at 5.3 million around 2050 and then slowly decline.
The projections also showed growing numbers of older people in coming decades.
The number of people aged 85 years and older would more than triple, from about 83,000 in 2016, to between 270,000 and 320,000 in the next 30 years.
Those aged 65 years and older would roughly double, from about 700,000 now to between 1.3 and 1.5 million in 2046.