Under pressure from other parties, the government is considering minimum pricing for alcohol following concerns booze is being sold too cheaply.

Experts and opposition parties criticised the government's Alcohol Reform Bill for failing to address alcohol pricing, among changes to where alcohol can be sold and the drinking age.

With the bill yet to have its final reading, Justice Minister Judith Collins told TVNZ's Q+A programme officials are looking at a minimum price regime for alcohol.

A minimum price could be included in last-minute changes to the legislation before it passes.

The government may also hike alcohol excise further, with Ms Collins saying "it's something that we'll look at in the future".

She said she supports a split purchase age, with 18-year-olds able to purchase alcohol at bars and restaurants, but only those over 20 able to purchase alcohol at off-licences, like bottle stores and supermarkets.

Ms Collins believes other MPs, who will have a conscience vote on the drinking age, will also support a split age.

The Maori Party also wants further changes to the bill, proposing limiting where alcohol products can be advertised and restrictions on the proximity of liquor stores to schools.