Since 1971, the United Nations has denominated "
Least Developed Countries" (LDCs) a category of States that are deemed highly disadvantaged in their development process (many of them for geographical reasons), and facing more than other countries the risk of failing to come out of poverty. As such, the LDCs are considered to be in need of the highest degree of attention on the part of the international community.
Three United Nations Conferences on the Least Developed Countries were held in 1981, 1990, and 2001 under the leadership of UNCTAD. The third conference (Brussels, 14-20 May 2001) agreed on the
Programme of Action for the Least Developed Countries for the Decade 2001-2010 . By periodically reviewing the list of LDCs on the basis of established criteria and highlighting their structural problems in relevant UNCTAD publications, the UN gives a strong signal to the development partners of these countries, and points to the need for special international support measures and concessions in their favour.
At the time of the 2003 review of the list, the following three criteria were used by the UN:
low income, in the light of a three-year average estimate of the gross national income per capita (under $750 for cases of addition to the list, above $900 for cases of graduation);

weak human assets, as measured through a composite Human Assets Index; and

- economic vulnerability, as measured through a composite Economic Vulnerability Index.
Recognition by the UN of the particular problems faced by LDCs brought the development partners of these countries, including UN agencies and programmes, to adopt a range of special support measures in their favour. These measures are essentially designed to reduce the competitive disadvantages LDCs suffer from in the global economy; support the development of their physical infrastructure and human resources; and enhance their institutional capacities. LDC-specific treatment mainly falls under three areas of international cooperation:
in the multilateral trading system, special concessions, such as non-reciprocal market access preferences (e.g. the European Union's "Everything But Arms" initiative), are granted to LDCs;
in the field of development financing, bilateral, regional and multilateral donors and financial institutions are expected to give LDCs specially favourable consideration in their decisions on concessionary financing; and
- in the area of technical assistance, priority is given to LDCs under all cooperation programmes of the UN, and bilateral and regional development partners are encouraged to follow the same preferential policy.