"The final draft of the agreement on a free trade zone between the EEU and Vietnam has been agreed," the source, who was present at an intergovernmental session between the two countries, told RIA Novosti.
The source added that the general agreement will allow Russian companies to assemble motor vehicles in Vietnam, as part of the documentation package signed by Medvedev in May.
"This entails the industrial assembly of Russian lorries and light commercial vehicles for further deliveries to the local market, and for re-export in third countries," the source said.
The source stressed that a free trade zone with Vietnam opens large opportunities to the EEU in South and Southeast Asia.
Vietnam became the first country to sign a free trade agreement with the EEU, which includes Russia, Armenia, Belarus, Kazakhstan and Kyrgyzstan.
The EEU, which came into force on January 1, aims to achieve the free flow of goods, services, capital and labor across its member states.