Effective January 1st, 2016, Russia is suspending its free-trade treaty with Ukraine.
Russian President Vladimir Putin is reported to have signed a decree citing "exceptional circumstances, which impact the interests and economic security of the Russian Federation."
Currently, Russia and Ukraine are engaged in trade in accordance with the free trade agreement between CIS countries. However, starting next year the economic part of Kiev's Association Agreement with the EU comes into force, making Ukraine part of the European trading bloc.
Putin's decision came on Wednesday, just hours after Ukrainian Prime Minister Arseniy Yatsenyuk said his government would ban commerce with the Russian-annexed peninsula of Crimea.