Brazil pushed for concerted action to alleviate hunger Monday as it hosted a summit of the Group of 20 leading economies amid global uncertainty over two major wars and incoming U.S. President-elect Donald Trump.

Set against a backdrop of political turmoil, it's going to be a big ask for the leading rich and developing nations to sign up to any meaningful declarations.

Brazilian President Luiz Inacio Lula da Silva opened a G20 summit in Rio by launching an alliance to curb world hunger, which he called a "scourge that shames humanity."The Global Alliance Against Hunger and Poverty marks an early summit success for left-wing Lula,