New Zealand must rely on foreign workers because too many locals are on drugs or “won't turn up for work”, its prime minister has said.

Defending the nation’s record migrant intake, John Key said New Zealand needed to import workers - even for low-skilled jobs - because not all locals were suitable or were prepared to move to less desirable areas.

He said the government had been looking to reducing its importation of workers from Pacific island nations to pick fruit but farmers did not want to rely on the locally unemployed population.

“Go and ask the employers, and they will say some of these people won't pass a drug test, some of these people won't turn up for work, some of these people will claim they have health issues later on,” he told Radio New Zealand.

“So it's not to say there aren't great people who transition … to work, they do, but it's equally true that they're also living in the wrong place, or they just can't muster what is required to actually work."

Government figures showed a record 69,000 people moved to the nation of 4.7 million people last year – and 200,000 people received temporary work visas - prompting calls from the opposition to limit migration to protect local workers.