The Ukraine-EU association agreement may not be signed, Russian presidential advisor Sergei Glazyev suggested.

"I think it will not be signed. This agreement cannot be signed because it is at variance with everything - Ukraine's economic interests, our spiritual and historical traditions - and it is disadvantageous for Europe, for us, for Belarus and Kazakhstan. In fact, it is disadvantageous for everyone except for several nonsensical politicians who are pushing this course," Glazyev said.

Ukraine breached the Amity Treaty, the backbone of Russia-Ukraine relations, when it initialed the deal, he said during a live program on the Rossiya 24 television channel.

"Article 13 of the Treaty of Amity with Ukraine committed us to reconcile our laws and to create a common economic space. The association agreement with the European Union blocks this opportunity, which means the Ukrainian administration violated its fundamental treaty with Russia, the entire foundation for bilateral relations," Glazyev emphasized.

The primary reason why the Ukrainian administration "makes such an odd decision is a sort of deception," he said. "Just like it happens in any treachery, this self-deception derives from personal interests of the people involved in the decision-making process. We know that many Ukrainian politicians and oligarchs are eager to legalize their money in the European Union; they have property and real estate there. And European partners are whispering in their ears: you do as we say and you will be just fine," the presidential advisor argued.

He also said that Russian and Ukrainian experts had made some estimates. "These estimates show that Ukraine will be witnessing a decrease in its economic growth and balance of trade until 2020 if it signs the association agreement with the EU and joins the unequal free trade zone. We estimate [their losses] at approximately -1.5% of GDP per year. These numbers are solid proof (…) no one questions them," Glazyev said.

But if Ukraine joins the Customs Union "it will immediately gain $10 billion in trade because of the shift to domestic gas pricing, we will not levy the export duty on crude delivered to Ukraine, and this will bring $5.5 billion," the advisor said.

"The market will be wide open for Ukrainian agro-industrial commodities, which will bring another $2 billion. And, besides, there will be vast cooperation in machine building, [an industry] entirely connected to Russia and offering growth prospects. There will be billions of dollars in joint projects which have been suspended due to the lack of clarity of what to do next," the Russian presidential advisor said.