” US Trade Representative Ron Kirk and US Agriculture Secretary Tom Vilsack said in a joint statement.

Russia’s ban on imports of US meat products over the feed additive ractopamine went into effect on Monday. Russia is concerned about the use of the growth stimulant used in US and other countries to make beef, pork and poultry products leaner. Some countries ban the additive out of concern that trace elements could remain in the meat and cause health problems. Russia enacted similar ractopamine requirements for producers Canada, Brazil and Mexico.