China's Sinovac Biotech has committed to provide 50 million doses of a coronavirus vaccine candidate to Indonesia's government from November to March, a minister and Indonesia's state-owned pharmaceutical company Bio Farma said.

The Southeast Asian nation is seeking to secure a supply as cases rise unabated.

During a visit to China, Indonesian Foreign Minister Retno Marsudi said a preliminary agreement had been signed with Sinovac for bulk purchase and supply of the vaccine, CoronaVac, from November to March, after which Indonesia's state-owned Bio Farma would get priority access until end-2021.

Indonesia has recorded 149,408 coronavirus infections and 6,500 deaths and is keen to secure a vaccine for its 260 million people and develop its own, amid concern among some developing countries about competition for access.

"Indonesia sees a strong commitment from China's industries to forge partnerships and a strong commitment from its government to foster those partnerships," she said late on Thursday via video.

Sinovac did not immediately respond to a request for comment on Friday and Bio Farma said in a statement on Friday evening that the 50 million bulk would come in stages: 10 million for each month starting in November. Marsudi said on Thursday that the doses had been 40 million.

Phase III trials for Sinovac's CoronaVac began last week in Indonesia involving 1,620 volunteers.

Bio Farma is involved in the development of the vaccine and has said Indonesia should have capacity to produce 250 million doses a year by the end of 2020, pending human trials.

In an interview with Reuters on Wednesday, research minister Bambang Brodjonegoro said Indonesia was developing its own COVID-19 inoculation, dubbed the "red and white" vaccine after the colors of the national flag.

Brodjonegoro expected production by Bio Farma to start sometime in 2021.

"Obtaining vaccines entails risk, uncertainty," he said. "Even if there are other countries or parties who have found effective vaccines, we need to make our own vaccine for COVID-19."