Acting Cuban President Raul Castro says counties in the southern hemisphere have no choice but to unite and take action to overcome common obstacles.
Mr. Castro made his comments Thursday during a summit of the Group of 15 developing nations taking place on the sidelines of the Non-Aligned summit in Havana.
Mr. Castro also called for more efforts to create a more "fluid and positive" North-South dialogue.
Iranian President Mahmoud Ahmadinejad and Venezuelan President Hugo Chavez also spoke at the meeting.
The G-15 of developing countries was established in 1989 at the end of the Non-Aligned Summit in the former Yugoslavia. It aims to foster greater cooperation among developing nations, particularly in the southern hemisphere.
The G-15 has grown to 19 member nations. They are: Algeria, Argentina, Brazil, Chile, Colombia, Egypt, India, Indonesia, Iran, Jamaica, Kenya, Malaysia, Mexico, Nigeria, Peru, Senegal, Sri Lanka, Venezuela and Zimbabwe.