The UK has pledged £200 million to the World Health Organisation (WHO) and other charities to help slow the spread of the coronavirus in vulnerable countries and to help prevent a second wave of infections.
More than 1.6 million people are reported to have been infected by coronavirus globally and deaths have topped 100,000.
Infections have been reported in 210 countries since the first cases were identified in China in December last year, and British aid minister Anne-Marie Trevelyan said assisting the poorest nations now would help prevent the virus returning to the UK.
Britain has reported almost 9,900 deaths from coronavirus so far, the fifth highest national number globally.
"While our brilliant doctors and nurses fight coronavirus at home, we’re deploying British expertise and funding around the world to prevent a second deadly wave reaching the UK," Mrs Trevelyan said.
"Coronavirus does not respect country borders, so our ability to protect the British public will only be effective if we strengthen the healthcare systems of vulnerable developing countries, too."
The British government said £130m would go to United Nations' agencies, with £65m for the WHO.
Another £50m would go to the Red Cross to help war-torn and hard-to-reach areas, with £20m going to other organisations and charities.
The cash would help areas with weak health systems such as war-ravaged Yemen, which reported its first case on Friday, and Bangladesh, which is hosting 850,000 Rohingya refugees from Myanmar in crowded camps, it said.
Britain's support for the WHO contrasted with the view of US President Donald Trump, who has criticised its handling of the Covid-19 pandemic with suggestions his administration might re-evaluate US funding
"The United Kingdom’s generous contribution is a strong statement that this is a global threat that demands a global response," Tedros Adhanom Ghebreyesus, the WHO's director-general, said.
"We are all in this together, which means protecting health around the world will help to protect the health of people in the UK."