A co-founder of Facebook has become one of the latest billionaires to pledge to give away the majority of his wealth.
Mark Zuckerberg is one of 17 new people to support a group founded by Microsoft's Bill Gates and his wife along with investor Warren Buffett, which encourages America's wealthiest to publicly promise to donate to charity.
At 26, Mr Zuckerberg is one of the youngest to sign up to The Giving Pledge, the BBC reports.
Mr Zuckerberg, estimated to be worth $US6.9 billion, was placed 35th in this year's Forbes list of the richest people in the United States.
Earlier this year, he gave $US100m in shares to schools in New Jersey.
The Giving Pledge initiative was launched earlier in the year. It was announced in August that 40 individuals or families had made the pledge.