The average individual U.S. producer will shoulder initial costs of $376 and the average U.S. retailer will face initial costs of $26,149, according to the latest estimate.

"There can be no doubt that implementing mandatory country-of-origin labeling is going to pose unique challenges to farmers, ranchers, packers and retailers," Dewey Maroney, the vice president of the California-based Raley's grocery store chain, advised the department during public comments.

Lawmakers originally mandated labeling rules in the 2002 farm bill, then stalled them under industry pressure, then reiterated them in the 2008 farm bill, which was enacted over President Bush's veto.

More than 1.2 million U.S. business "establishments" will be "either directly or indirectly affected" by the new labeling requirements, the department estimates.

The country of origin may be conveyed through stick-on labels, tags, placards or other devices in bins or on packaging.

Businesses will have to keep country-of-origin records for one year after transactions. The 2002 farm bill initially set a $10,000 penalty for each violation. Lawmakers lowered that to $1,000 in the 2008 farm bill and reduced some paperwork requirements.