The top U.S. and South Korean trade envoys broke off talks Sunday without resolving a crisis over the resumption of American beef shipments that has shaken South Korea's pro-U.S. government, reported CNN.
Tens of thousands hold up candles in South Korea during last week's protest against resuming beef imports.
South Korean Trade Minister Kim Jong-hoon, who flew into Washington on Friday for discussions, was returning home, U.S. Trade Representative spokeswoman Gretchen Hamel said.
Kim and Susan Schwab, the U.S. trade envoy, held "frank and candid discussions" Friday and Saturday, Hamel said, but, "in order to find a mutually acceptable solution, both sides need more time to look into technical issues."
She said officials from the countries will stay in contact.
The talks, which focused on the importation of U.S. beef from cattle below 30 months of age, came as thousands of people protested in Seoul, demanding that a beef import deal settled in April be renegotiated and urging South Korean President Lee Myung-bak to resign.
Lee has vowed not to allow the import of beef from cattle older than 30 months. Scientists think infection levels of mad cow disease increase with age.
The Bush administration has said that it will not renegotiate an accord that was supposed to have settled a major irritant in ties between the allies.
But Washington has said it supports beef packaging labels that would show the ages of slaughtered cows. Kim wanted Washington to approve measures under which the beef industry would agree voluntarily not to ship meat from cattle older than 30 months, even though the April beef pact would allow such shipments.
American beef processors have said they are willing to label beef shipments bound for South Korea.
South Korea was the third-largest overseas market for U.S. beef until it banned imports after a case of mad cow disease was detected in 2003, the first of three confirmed cases in the United States.
Mad cow disease is the common term for a brain-wasting disease in cattle called bovine spongiform encephalopathy, or BSE. In people, eating meat contaminated with BSE is linked to variant Creutzfeldt-Jakob Disease, a rare and deadly nerve disease.