Russia on Monday warned that it might soon bar imports of U.S. and Canadian beef and pork if producers do not certify them free of the feed additive ractopamine.
The potential ban could jeopardize more than $500 million a year of exports to Russia and coincides with mounting U.S.-Russian tensions over trade and human rights.
Alexei Alexeyenko, spokesman for the Veterinary and Phytosanitary Inspection Service, said chilled products could be banned starting Feb. 4 and frozen meat starting Feb. 11.
Ractopamine is a growth stimulant used to make meat leaner. Despite scientific evidence stating that it is safe, it is banned in some countries because of concerns that residues could remain in the meat and cause health problems.