Health Minister Dr David Clark admits the mental health sector is short thousands of workers and has "significant gaps" in the system.
Appearing on The AM Show on Thursday, Dr Clark refused to say how much funding the sector would get in the budget, but admitted it would take time to sort the issues out.
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"One in five New Zealanders might be struggling with a mental health issue and we need to support those," he said. "We need to make sure everyone who needs support gets it.
"Across the country we are going to have to make sure there are people in the primary care setting to respond to that."
Dr Clark said the Government's mental health inquiry, of which the details were released in December, exposed the problems in the sector.
He said people who were at the mild to moderate end were not getting support early enough.
"Everyone knows a family member or friend who has struggled with mental health, without the support they need," he told The AM Show.
"We need to do something about that."
The official Budget announcement will be made at 2pm.