The paper considers the problems of developing recommendations in the area of fiscal and trade policies to counter economic sanctions at the level of both individual countries subject to such sanctions and at the level of economic union including such countries. Research study has been carried out based on the developed dynamic multi-sectoral and multi-country computable general equilibrium model, which describes the functioning of the economies of nine regions of the planet, including five countries of the Eurasian Economic Union (EAEU). The initial data of the model contain built sets of consistent social account matrices (SAMs) for the historical and forecast periods based on data from the Global Trade Analysis Project (GTAP) database, national input-output tables, international trade and IMF data (including forecast) for the main macroeconomic regions indicators. Results of the impact on macroeconomic and sectoral indicators of the EAEU countries and other regions of a hypothetical scenario providing the imposition of additional economic sanctions since 2019 against Russia from some regions were obtained. An approach to solving problems to counter the sanctions policy based on the parametric control theory by setting and solving a number of dynamic optimization problems to determine optimal values of the corresponding fiscal and trade policy instruments at the level of individual EAEU countries and the EAEU as a whole was proposed. The results of the model-based calculations were tested for the possibility of practical application using three approaches, including evaluation mappings’ stability of the exogenous parameters’ values of a calibrated model to the values of its endogenous variables. The results demonstrate greater efficiency for each EAEU country using a coordinated economic policy to counter sanctions, compared with the implementation of such policy separately at the level of each country.