The resumption of India supplying COVID-19 vaccines to the global COVAX vaccine-sharing platform after eight months was delayed on Monday when Nepal requested a postponement, two sources told Reuters.

The Serum Institute of India (SII), the world's biggest vaccine maker, was scheduled to ship Covishield doses through COVAX to Nepal on Monday, but the country now wants them only around Nov. 29, said one of the sources, a Nepal health ministry official.

He declined to explain the reasons for the delay. Neither source wanted to be named ahead of vaccine delivery, expected to be in hundreds of thousands of doses.

A Nepal health ministry spokesperson had no immediate comment. SII, whose licensed version of the AstraZeneca (AZN.L) vaccine is known as Covishield, did not respond to a request for comment.

SII last supplied to COVAX in the middle of April before India stopped all vaccine exports to meet its own demand as infections soared. The company has a deal to sell hundreds of millions of vaccines doses to COVAX, which distributes shots to low and medium-income countries.

Before the ban, SII sent a total of about 20 million Covishield doses to various countries through COVAX and many more doses as part of the Indian government's vaccine grants programme.

India last month sent around 4 million vaccine doses bilaterally to its friends and neighbours after domestic output surged. SII has nearly quadrupled Covishield production to up to 240 million doses a month from its April levels

India has resumed a small amount of exports of COVID-19 vaccines and will increase exports significantly in the next few months as domestic stocks build up and most of its own large population is inoculated, officials said on Wednesday.

One million shots of Covaxin produced by Indian company Bharat Biotech were shipped to Iran last week, the Indian embassy in Tehran said.