The International Day for South-South Cooperation, observed on September 11, promotes cooperation and knowledge-sharing among developing countries. The 2026 observance saw the launch of the Global Alliance for South-South and Triangular Cooperation, a voluntary UN-facilitated platform convened by the UN Office for South-South Cooperation (UNOSSC). South-South Cooperation lets developing nations share knowledge, technology, skills and solutions, while Triangular Cooperation adds support from developed countries or international bodies. The 2026 theme is “Solidarity Rising: Global Alliance for Inclusive and Innovative Development.”