The UK is to pledge £212 million to help a million girls living developing Commonwealth nations go to school for longer, Theresa May is to announce.
The Prime Minister will pledge cash with the aim of helping children spend 12 years in school when she gives a speech at the Commonwealth Heads of Government Meeting (CHOGM) in London on Tuesday.
In front of an audience expected to include Microsoft founder, philanthropist and anti-malaria campaigner Bill Gates, she is also expected to urge leaders from the bloc's 53 nations to work to halve the number of those afflicted by 2023.
Mrs May is due to say that the 12-year figure agreed by experts as the length of time children should be schooled to reach their full potential should be the "the goal for all our members".
She will say: "Across the Commonwealth, tens of millions of young people - usually but not always girls - are denied the education that would allow them to get on in life.
"All too often young people receive only the most basic education before being forced out of school through discrimination, poverty or simply the expectations of society."
A Downing Street spokeswoman said the money would "see nearly one million more girls in developing Commonwealth countries being able to go to school".
On Monday Mrs May highlighted the importance of getting women into work, and cited estimates that global GDP could be increased by up to 28 trillion US dollars (£20 trillion) if women played the same role as men in the labour market.
CHOGM occurs every two years to discuss shared interests and challenges.
Mrs May is also due to set her sights on malaria, one of the world's deadliest diseases.
She will say: "The UK remains committed to its five-year pledge, made in 2016, to spend half a billion pounds a year tackling malaria.
"This year, that figure includes £100 million that will be match-funded by partners in the private sector.
"I know other Commonwealth nations are also among the biggest funders of this global effort.
"Malaria devastates lives worldwide but it has a particular impact on the Commonwealth. And we, as a Commonwealth, have a particular duty to tackle it."