Italian President Sergio Mattarella, former Brazilian President Luiz Inacio Lula da Silva and a handful of agriculture ministers have given a boost to the U.N. goal of eliminating world hunger by signing the so-called Milan Charter.

The Italian government intends the charter to be the legacy of the six-month Milan Expo 2015 world's fair, which ends October 31. Mattarella said the charter has "great ethical and political value" by indicating crucial goals and asking for "tough changes" in behavior and regulation.

The agriculture ministers of Angola, Argentina and Iran, who attended a two-day meeting on the charter's themes, were among those who signed the document.

More than 200,000 people have signed the document, which seeks action toward such goals as reducing food waste.