New York  - The meeting of the world's 20 leading economies in London on April 2 has the potential of making profound changes in the global economy that is suffering a deep recession, United Nations Secretary General Ban Ki-moon said Monday.

"The stakes at the London summit are large," Ban told the UN General Assembly, which convened to discuss the world economic downturn, triggered initially by a US financial crisis and which threatens funding for UN programmes.

"The social fallout has been so severe that it could soon evolve into a wholesale political crisis, with instability and unrest in many parts of the world," Ban said.

He said the Group of 20 meeting in London can kickstart the world economy, find ways to prevent a future crisis and place the world "on a more equitable, sustainable path for the future."

He called for "global social justice" as world leaders at the meeting can institute change to help the poor around the world impacted by the recession. He called for standing against protectionism and opening up trade by breaking the deadlock in the Doha negotiations.

"In London, I will ask the G20 leaders to commit themselves to sealing a climate change deal in Copenhagen later this year," Ban said, referring to the final round of talks to renew the Kyoto Protocol in December before its expiration in 2012. The protocol deals with greenhouse gas emissions that contribute to global warming. (dpa)