If Ukraine joins the Customs Union, export duties for energy may be cancelled, while overall Ukraine's profit from such an action may be up to $9 billion, Russian presidential advisor Sergei Glazyev said.

"There are no duties, either export or import ones, in the Customs Union. That is why the first thing Ukraine will get if it joins the Customs Union is the cancellation of export duties for oil and gas," Glazyev told a bridging in Moscow.

"Overall improvement of trade conditions for Ukraine if it joins the Customs Union will be $9 billion," he said.

"This is a direct advantage to the Ukrainian trade balance, given the fact that the deficit of the country's balance of payments is over $5 billion, which is a threat to the stability of hryvnia," he said.

The Customs Unions entry will allow Ukraine to stabilize its financial situation and ensure stable demand for its national currency, he said. "This is a vital issue for Ukraine," Glazyev said.

Also Ukraine will get such preferences as access of agricultural products to the Customs Union market, he said.

Moreover, Customs Union entry will allow to improve Ukraine's economic activity by 17% of GDP in 10 years. "That is why we hope for common sense and understanding of our common interests," Glazyev said.

Ukraine's involvement in the Customs Union is "so natural and logical, that I am sure that sooner or later the country will join," he said, noting that the dragging on of negotiations reduce the economic effect.