UN food chief David Beasley called on the world's billionaires on Thursday to step up to help save some 30 million people he said are at risk of dying if they don't receive help from the World Food Programme.

Globally some 270 million people were headed toward the brink of starvation and WFP hopes to reach 138 million people this year, Beasley told the UN Security Council

"We need $4.9 billion to feed, for one year, all 30 million people who will die without WFP's assistance," Beasley said, noting that there are some 2,000 billionaires with a net worth of $8 trillion and several made billions during the pandemic.

"I am not opposed to people making money, but humanity is facing the greatest crisis any of us have seen in our lifetimes," said the former South Carolina governor.

The combined wealth of America's billionaires jumped over 19% or by half a trillion since the outbreak of the novel coronavirus pandemic in the United States, according to a report published by the Institute for Policy Studies (IPS) in June.

In the 11 weeks from March 18, when lockdowns started in some US states, Amazon.com Inc founder Jeff Bezos saw his wealth soar by about $36.2 billion, while Facebook Inc CEO Mark Zuckerberg's fortune surged by about $30.1 billion. Tesla Inc Chief Executive Elon Musk's net worth also rose $14.1 billion.

It's time for those who have the most to step up, to help those who have the least in this extraordinary time in world history," Beasley said. "The world needs you right now and it's time to do the right thing."