Please answer a question about the following article about Tuvalu:

The United Nations designates Tuvalu as a least developed country (LDC) because of its limited potential for economic development, absence of exploitable resources and its small size and vulnerability to external economic and environmental shocks. Tuvalu participates in the Enhanced Integrated Framework for Trade-Related Technical Assistance to Least Developed Countries (EIF), which was established in October 1997 under the auspices of the World Trade Organisation. In 2013 Tuvalu deferred its graduation from least developed country (LDC) status to a developing country to 2015. Prime Minister Enele Sopoaga said that this deferral was necessary to maintain access by Tuvalu to the funds provided by the United Nations's National Adaptation Programme of Action (NAPA), as "Once Tuvalu graduates to a developed country, it will not be considered for funding assistance for climate change adaptation programmes like NAPA, which only goes to LDCs". Tuvalu had met targets so that Tuvalu was to graduate from LDC status. Prime minister, Enele Sopoaga wants the United Nations to reconsider its criteria for graduation from LDC status as not enough weight is given to the environmental plight of small island states like Tuvalu in the application of the Environmental Vulnerability Index (EVI).

What organization sponsors an assistance program for least developed countries?
World Trade Organisation