The core activity of the Section for External Relations (REX) includes monitoring the EU's external activities by conducting dialogue with civil society organisations in the non-EU countries and regions with which the EU has formal relations, particularly in the candidate countries and in the EU's neighbourhood. The Section actively follows the EU's trade and development policies.

The EESC's external relations are conducted mainly as a response to mandates received through international agreements signed by the EU with third countries, or by decisions taken at Head of State summits. The REX Section works with ACP countries, Latin America & Caribbean countries, the USA, Canada, Euro-Mediterranean partners, Ukraine, Georgia, Moldova, Turkey, the Western Balkans, Russia, China, Japan and Korea.