Billionaire Saudi Arabian Prince Alwaleed bin Talal has said he will give his $32bn (£20bn) fortune to charity when he dies.

The prince, already known for his ostentatious charitable donations, told reporters on 1 July that he would begin moving the considerable wealth to his Alwaleed Philanthropic Foundation over the coming years.

The $32bn will include Prince Alwaleed's stake in Kingdom Holding, the investment firm he chairs, as well as his assets outside Saudi Arabia.

In a statement read to reporters at a conference in Riyadh, the prince said his pledge "will help build bridges to foster cultural understanding, develop communities, empower women, enable youth, provide vital disaster relief and create a more tolerant and accepting world".

He said the donation "will be allocated according to a well-devised plan throughout the coming years" but added there was no time limit on when the donation should be spent.

It is a commitment without boundaries. A commitment to all mankind. - Prince Alwaleed bin Talal

"It is a commitment without boundaries. A commitment to all mankind," Alwaleed said.

He said that the Bill and Melinda Gates Foundation, which has focused on donating money to education and world health initiatives, was his inspiration.

The Saudi prince, nephew to the late king Abdullah, said he would head a board of trustees tasked with spending the money. After he dies, his son will become president of the board of trustees and his daughter the vice president, Arabianbusiness.com reported.

Alwaleed made the statement alongside his two children, Prince Khaled and Princess Reem. He said both were supportive of his decision.

In April Prince Alwaleed promised to give each of the 100 fighter pilots that took part in Riyadh's latest air strikes in Yemen a brand new Bentley. After a backlash on Twitter, in which he holds a $300m stake, the prince withdrew the pledge.

As well as media investments, Kingdom Holding has interests ranging from the Euro Disney theme park and Apple to Four Seasons hotels and Citigroup.