Britain will start delivering 9-million doses of Oxford-AstraZeneca Covid-19 vaccine this week to countries including Indonesia, Jamaica and Kenya to help tackle the pandemic, the government said on Wednesday.

Some 5-million doses were being offered to COVAX, the scheme to ensure equitable, global access to Covid-19 vaccines, while another 4-million doses will be shared directly with countries in need.

"The first batch - 9-million doses - will be going out on Friday," Foreign Secretary Dominic Raab told broadcasters, adding that they would go to countries including Laos, Cambodia, Indonesia, Malaysia, Kenya and Jamaica.

"We're not just doing it because it's in our own interest, it shows global Britain as a life saving force for good in the world," he said.

Indonesia will receive 600 000 doses, 300 000 will be sent to Jamaica and 817 000 will go to Kenya, among other countries, the government said.

British Prime Minister Boris Johnson pledged to donate at least 100-million surplus Covid-19 vaccines within the next year as a contribution to the efforts of the G7 to help poorer countries inoculate their citizens.

The donation announced on Wednesday is the first tranche of that pledge, the government said.

The announcement came as Johnson was due to meet Kenya's President Uhuru Kenyatta in Britain.