Australia will give an extra $50 million to the global effort to widen COVID-19 vaccination of people in low and middle-income countries.
Prime Minister Scott Morrison said the contribution to the COVAX Advance Market Commitment would bring Australia's total to $130 million.
It will assist in delivering more than 1.8 billion doses worldwide, reaching at least 114 million people in Southeast Asia and the Pacific.
The funding complements Australia's $623 million regional vaccine access initiative.
"Our neighbours in the Pacific and Southeast Asia have now received more than 13 million doses from COVAX, with more deliveries planned," Mr Morrison said in a statement on Thursday.
"These vaccines are being prioritised for high-risk individuals, health workers, frontline personnel and vulnerable groups."
Save the Children's Sarah Carter said the contribution was welcome but there was a long way to go.
"There is an urgent need to ensure vaccination coverage is truly global because it is the only way to help bring an end to this pandemic," she said.
"It's simply not acceptable that the world's poorest countries have received just 1.3 per cent of the world's vaccines."