New Zealand's Prime Minister Jacinda Ardern has called Australia's policy of deporting foreign nationals convicted of committing crimes "corrosive" in a heated press conference with her Australian counterpart Scott Morrison.

It comes after the Australian government stepped up deportations of foreign-born criminals in recent months.

The move has seen hundreds of people deported from Australia to New Zealand, a country that some left at a young age and now have few ties to.

Prime Minister Morrison defended the policy, saying: "If you have committed a crime, and you're not a citizen of Australia, then you have no right to stay."