Mexico has joined a growing list of countries temporarily banning U.S. beef imports, following a case of mad cow disease on a farm in the western U.S. state of Washington.
Mexico is the second-largest importer of U.S. beef, after Japan.
The Mexican announcement follows similar bans by Japan, South Korea, Singapore, Malaysia, Taiwan, Australia, Russia and Thailand. The Reuters news agency says Turkey and Chile are also imposing bans, and that Brazil is considering such action.
The import restrictions come as U.S. agriculture officials are investigating the path of a slaughtered cow with mad cow disease in Washington state. They are checking processing plants to see whether any by-products reached the American public.
U.S. Agriculture Secretary Ann Veneman says her agency is preparing an initial recall of about 4,500 kilograms of beef that may have been tainted. But she said U.S. officials remain confident that the nation's food supply is safe and that the current risk to human health is minimal.
Investors, however, reacted negatively to the news. Shares of fast food hamburger giant McDonald's dropped at least six percent in opening trade, Wednesday.
Humans who eat meat from infected cows can acquire a brain disease that leads to paralysis and death. The disease has killed more than 100 people worldwide since it was discovered in Britain in 1986
Mad cow disease (bovine spongiform encephalopathy) is spread when cows eat cattle feed that includes ground products from cows already infected with the illness.