The total number of finalised adoptions has fallen 63 per cent over the past 25 years, the Australian Institute of Health and Welfare's report says.

And in the year 2020-21, the number declined 21 per cent, with only 264 adoptions finalised.

Of these, 222 were domestic - a decline of 25 per cent from the previous year and the lowest number recorded in the past five years.

Only 42 were "intercountry" adoptions, with almost all children coming from Asian countries like Taiwan (36 per cent), South Korea (29 per cent) and Thailand (14 per cent).

"Travel restrictions associated with government responses to COVID-19 and the noted impact of the pandemic on visa applications likely contributed to the low number of intercountry adoptions finalised during 2019-20 and 2020-2021," the report says.

"It is possible that some adoptions that would have otherwise been finalised during the year will appear in national data for subsequent years."

However, irrespective of the pandemic, official intercountry adoption figures have been declining in recent years, the AIHW says.

Australians living abroad who adopt through an overseas agency or government authority are not included in these statistics.

The only involvement the Australian government has with "expatriate adoptions" is when these families apply for visas for their adopted children.

In the year 2020-2021, 27 such adoption visas were granted by the Department of Home Affairs.

Three fifths of these applications came from families living in countries that Australia has never had a formal adoption program with.

Local adoptions will also have been affected by the pandemic, the report says, after travel restrictions, lockdowns, quarantine requirements and limitations on non-urgent face-to-face work were put in place.

Australian Associated Press