Mexico has suspended meat imports from 30 processing plants in 14 states, including Smithfield Packing Inc., which is based in North Carolina.
The news was released on the U.S. Department of Agriculture Web site.
Smithfield is the world's largest pork slaughterhouse.
According to the Associated Press, other companies that will be affected by this move are Tyson Foods, Inc., Cargill Inc., ConAgra Foods Inc., and Swift Foods Inc.
The ban could greatly affect Tyson because high feed prices have already strained its profits and Mexico represented 23 percent of its international sales in 2008.
Authorities believe the suspensions may be in retaliation for the U.S. putting a country-of-origin labeling law into effect earlier this year in response to concerns the safety of imports.
The country-of-origin labeling law mandates the separation of foreign cattle and pigs in U.S. feedlots and packing plants. Foreign animals are also now required to have more documentation about where they come from and have tags that indicate they are free of mad cow disease.
