Japanese officials say they are temporarily banning U.S. beef imports, following detection of a case of mad cow disease on a farm in the western U.S. state of Washington.
Japan is one of the top importers of U.S. beef.
Earlier Tuesday, U.S. Agriculture Secretary Ann Veneman announced the first known case of mad cow disease in the United States. But she said officials remain confident in the safety of the nation's food supply, and the risk to human health is minimal.
She said, however, it is too early to tell if this is an isolated case.
Ms. Veneman said the incident is not related to terrorism and is in no way linked to the nation's heightened Code Orange terror alert status.
The announcement led to an immediate drop in the stock prices of companies such as international fast-food chain McDonald's, a large user of beef.
A U.S. agriculture official told the Reuters news service U.S. officials will be recalling beef products once they have proper information about the meat.
Mad cow disease, bovine spongiform encephalopathy, is spread when cows eat ground-up cattle feed that includes products from cows already infected with the illness. Humans who eat meat from infected cows can acquire a brain disease that leads to paralysis and death.
The disease has killed more than 120 people since it was discovered in Britain in 1986.
Some information for this report provided by AFP and Reuters.