Prime minister Theresa May has urged international leaders at the G20 summit in Japan to follow the UK's lead and commit to fighting the world’s three biggest infectious disease killers, as she unveiled a £1.4 billion funding pledge.

In one of her final acts as prime minister Mrs May announced the UK would give £467 million a year over the next three years to the Global Fund to Fight Fight Aids, Tuberculosis and Malaria.

In October this year the Global Fund will host its three-yearly “replenishment” conference when it will seek contributions covering the period 2020 to 2023. It is looking for $14bn - a 15 per cent increase on its last fundraising round in 2016 when it raised just over $12bn.

The fund says the billions of dollars it hopes to raise will help save 16 million lives, cut the mortality rate from HIV, TB and malaria in half and build stronger health systems.

Mrs May said “urgent international action and a truly collective response” was needed to tackle the three diseases.