The assistance package would significantly bolster Cambodian efforts in vaccinating 80 per cent of its 16 million people against the virus as soon as practicable, the Australian embassy and the Cambodian government announced on Monday.

"In recognition that nobody is safe until everyone is safe, our support is likely to help vaccinate at least 1.5 million Cambodians and will go a long way towards supporting widespread access to WHO-approved vaccines in Cambodia," Australian ambassador Pablo Kang said.

The funding is in addition to this year's Cambodia aid budget of $66 million.

China has promised one million doses of its Sinopharm vaccine for 500,000 people, which requires two jabs per person and is expected to be available later this month.

Promises from Beijing have also been made to Myanmar, Indonesia, and The Philippines amid claims China is using the vaccine for diplomatic leverage with vaccine deliveries also tied to trade and investment deals.

Foreign assistance packages are in addition to vaccines Cambodia will receive from the multilateral WHO-COVAX facility, which Australia has also made significant contributions to and will cover up to 20 per cent of Cambodians for free.

Mr Kang said the Australian package would also help Cambodia to distribute and administer vaccines, to monitor the safety and efficacy of vaccinations, and to ensure Cambodians have access to clear information about the vaccination process.

"As a neighbour and longstanding friend of Cambodia, we are pleased to be able to lend a hand in this time of need," he said.

Cambodia has emerged relatively unscathed from the pandemic with just 466 reported COVID-19 cases, nearly all among people arriving from abroad. To date, there have been 443 recoveries and no deaths.

"Provision of this vaccine support reiterates Australia's sustained support and long-term commitment to our socio-economic development and our promising future," said Cambodia's Deputy Prime Minister Aun Pornmoniroth.

Australian Associated Press