Prime Minister Scott Morrison says Australia will take a cautious approach on expanding coronavirus vaccines to children under the age of 16.

Australia will take a cautious approach to approving coronavirus vaccinations for children, with experts warning the move is crucial to combating the Delta variant.

Leading epidemiologists and public health experts have called for the rollout to include people under 16 when other age groups are offered vaccinations.

Pfizer has applied to the medicines regulator to have the approval age for its vaccine lowered from 16 to 12.

Prime Minister Scott Morrison said the government took a cautious route in giving the green light to Pfizer and AstraZeneca for use in people over 16.

"We'll take the same approach here when it comes to the impact on younger Australians under the age of 18, under the age of 16," he told ABC radio on Thursday.

"Of course we're going to be cautious about that."

Doctors have pointed to emerging evidence showing six per cent of children infected with Delta suffered long-term symptoms while one in 1000 died.

"The fact that COVID can and does kill and disable young people is well known around the world," the Australian Medical Association's Andrew Miller said earlier in the week.

The NSW government has flagged it wants to vaccinate children when older age groups are immunised.

But the rollout is yet to be expanded to people under 40 nationally, with Pfizer supplies not at the levels needed to vaccinate younger people.

Mr Morrison said the government had been looking at vaccinating children but he wouldn't pre-empt the Therapeutic Goods Administration's advice.

Cabinet ministers will on Thursday receive a briefing from Chief Medical Officer Paul Kelly and health department boss Brendan Murphy on the issue.

US President Joe Biden has called for children aged 12 to 15 to be vaccinated after his country's regulator approved Pfizer for that age group.

The United Kingdom has decided only to offer children extremely vulnerable to coronavirus or those who live with someone at risk a jab.

"Different countries have had different approaches on that," Mr Morrison said.

"The TGA is working through that and I'll wait and see what their recommendations are."