Bill Gates has pledged to give away 99 per cent of his remaining fortune to his charitable foundation over the next 20 years.
The 69-year-old billionaire co-founder of Microsoft also lashed out at Elon Musk, accusing the world's richest man of "killing the world's poorest children" through huge cuts to the US foreign aid budget.
Mr Gates said he was speeding up his plans to donate $US200 billion ($312 billion) to the Gates Foundation — a nonprofit fighting poverty, disease, and inequity around the world — and would close the foundation on December 31, 2045, years earlier than previously planned.