With Russia a major buyer of food from the United States and Europe, the ban marks a deep escalation of an economic tit-for-tat set off by the crisis in Ukraine, which has brought East-West relations to their lowest since the Cold War.

Putin signed a decree on Wednesday halting or limiting imports of agricultural products from countries which have imposed sanctions on Russia, ordering his government to come up with a list of imports to be banned for a year.

"(All food products) that are being produced in the U.S. and being supplied to Russia will be banned," Ria Novosti quoted Alexei Alekseenko, spokesman for the VPSS food standards agency, as saying. "Fruit and vegetables from EU will be covered by the total ban," he added.

No one was available for comment at the VPSS (Phytosanitary Surveillance Service) but earlier Alekseenko told Reuters that retaliatory action would be "quite substantial", and include U.S. poultry.