Scott Morrison said he "welcomes" Western Australia's potential requirement that visitors from NSW be vaccinated before entering the state.
Asked if other states should consider it, the PM said "I do welcome the requirements for vaccination".
"This is for people who are otherwise getting an exemption to come into Western Australia, and the Premier has added that is not unlike the sort of things we have been talking about for some time, where people are vaccinated, and an exemption being given on public health grounds," he added.
"So I think that is really consistent with what the national plan is seeking to achieve, and as I said last week, all Premiers and Chief Ministers agreed to that."