CHAPTER IV REGIONAL ECONOMIC COMMUNITIES Article 28 Strengthening of Regional Economic Communities 1. During the first stage, Member States undertake to strengthen the existing regional economic communities and to establish new communities where they do not exist in order to ensure the gradual establishment of the Community. 2. Member States shall take all necessary measures aimed at progressively promoting increasingly closer co-operation among the communities, particularly through co-ordination and harmonisation of their activities in all fields or sectors in order to ensure the realisation of the objectives of the Community. 23