South Korea has reissued its ban on U.S. beef, citing a disagreement on importation and health safety codes. According to South Korean officials, inspectors also found a piece of cow bone in the beef; South Korean agriculture authorities have banned the importation of beef bones over fears of mad cow disease.

South Korea, which used to be the third largest market for U.S. beef, suspended importing U.S. beef in 2003. It lifted the import ban last year but imposed it again in August this year.

The repeated beef import suspension is a major trade issue between the two countries and is seen as a stumbling block to their negotiations for a comprehensive free trade agreement.