KIEV, Sept. 3 – If Ukraine signs an association agreement with the European Union, the Ukrainian-Russia basic treaty of friendship and cooperation will be violated, said Kremlin aide Sergei Glazyev.

"By signing the association agreement, Ukraine will violate Article 13 of the basic treaty, which says that our countries 'will refrain from moves that could do economic harm to each other, coordinate their financial, monetary-lending, budget, currency, investment, price, tax, trade and customs policies, and deepen economic integration on the basis of mutual benefit and harmonization of economic laws'," he said in an interview with Kommersant-Ukraina published on Tuesday.

By opting for association with the EU, Ukraine is departing from Article 13 of the Treaty of Friendship, Cooperation and Partnership with Russia, he said. "This does not mean we will reconsider the Treaty, but we will have to take note of the fact that Ukraine is making a unilateral decision without consulting with Russia, which makes the implementation of this article impossible," Glazyev said.