David Seymour says drug-purchasing agency Pharmac must be on its game, with a $604 million funding boost over four years.

The Government has announced it'll fund up to 26 cancer medications and 28 other treatments, as a pre-commitment against Budget 2025.

The Associate Health Minister says there's very few things he's in favour of spending more money on - but medicine is one of them.

"If you look at the amount of Government spending that goes on medicine - New Zealand is not just a bit below average, we're way behind the pack."

LISTEN ABOVE