"There is a kick-off already in the negotiation process and we estimate that it is going to take from 12-18 months," Mohamed Elbadri told Sputnik.
At this stage of negotiations, the envoy added, each party will study the benefits of mutual cooperation before entering into direct talks regarding the details of the agreement.
The treaty should cover all trade in commodities between the countries.
The Russia-led EEU officially came into force on January 1. The bloc aims to achieve the free flow of goods, services, capital and labor across its member states, with provisions for a greater integration in the future.
Last week, Russian Prime Minister Dmitry Medvedev approved a free trade zone agreement between the EEU and Vietnam.