The secretary of state for International Development Penny Mordaunt said the funds would help save an extra 50,000 people through education and decontaminating 5 million square metres of mined land.
“This will allow the poorest people to grow crops and their children to walk to school in areas which were once off limits,” she said.
“Landmines are deadly devices, that have no place in today’s world. No one should be forced to live in fear of losing a limb, their life or a child to these cruel, indiscriminate killers.”
Last year, DfID made a £100m commitment to make 15 million square metres of land safe again over a three-year period.
The additional £3m will go to South Sudan, Somalia, Zimbabwe, Burma and Cambodia for a three-month period.