Leaders of the global scheme aiming to get Covid-19 vaccines to the world's poorest are pushing manufacturers to cut or slow deliveries of about half a billion shots so doses are not wasted.

Moderna and Gavi have agreements for up to 650 million doses of the company's vaccine to be made available to Covax participants through 2021 and 2022.

North Korea is not known to have imported any Covid-19 vaccines, though media reports have suggested at least some key people, such as border control officials, may have been vaccinated.

WHO says the rapid cash injection into its Access to Covid Tools Accelerator could finish off Covid as a global health emergency this year.

But Covax has fallen far short of its initial objective of delivering two billion doses by the end of 2021.

More than 30 poorer nations, including big states such as the Democratic Republic of Congo and Nigeria, have used fewer than half of the doses they received.

Antony Blinken says Malaysia's ability to distribute excess vaccines to other countries is 'evidence of real leadership'.

Single-dose Johnson & Johnson shots will be provided to areas of conflict and other humanitarian distress.

The world's biggest vaccine maker resumed exports of Covid-19 doses this month for the first time since April sending about 4 million to countries such as neighbouring Bangladesh and Iran, but none to Covax.

The government says more than 300 million vaccine doses will be produced in October and one billion in the last three months of the year.

The vaccine-sharing facility says it now expects to access just 1.425 billion vaccine doses this year – far short of its goal of delivering two billion doses by year-end.

President Xi Jinping also pledges to donate US$100 million to Covax.