SEOUL , South Korea ( CNN ) -- South Korea will open its market to most U.S. beef , a senior government official said Thursday , according to state media . Thousands of people have taken to the streets of the South Korean capital in protest at the deal . South Korea banned imports of U.S. beef in 2003 amid concerns over a case of mad cow disease in the United States . The ban closed what was then the third-largest market for U.S. beef exporters . It resumed limited imports last year -- allowing boneless beef from cattle under 30 months of age -- but that re-opening was subject to interruptions and closed altogether in October 2007 . A deal that South Korea and the United States struck last month bans the import of high-risk materials , like tonsils , brains , spinal cord marrow and a section of the small intestine , Agriculture Minister Chung Woon-chun said Thursday , according to South Korea 's Yonhap news agency . These parts pose the greatest risk of transmitting mad cow disease to humans . The ban will be lifted within a few days , once the government 's new import rules have been published . The pending resumption of U.S. beef imports has n't been without political costs for President Lee Myung-bak . He apologized to the nation last week for failing to fully understand concerns about mad cow disease . In downtown Seoul , thousands of people have regularly staged protests , chanting `` We do n't want crazy cows , '' since the deal to revive beef imports was announced . And the main opposition party has taken up the fight . `` We will be forced to make a critical decision if the government pushes through its plan to announce resumption of beef imports , '' said Sohn Hak-kyu , leader of the main opposition United Democratic Party , Yonhap reported . `` If the government and the ruling party ignore this warning , we will come up with every possible measure to stop them . '' The opposition has already filed a suit to suspend implementation of new beef import terms , according to Yonhap . Lee 's ruling Grand National Party ( GNP ) is working to soothe tensions , saying that American beef is safe to eat and that adequate safety precautions have been taken . `` The government has tried its best to free the public from unnecessary concerns , and sufficient countermeasures have been prepared , '' said Lee Hahn-koo , the party 's chief policymaker , Yonhap reported . When South Korea and the United States reached the deal in April to re-open the South Korean market , they removed the major obstacle to U.S. congressional approval of the Korea-U.S. Free Trade Agreement ( FTA ) . Lee urged the National Assembly this month to ratify the agreement as soon as possible to provide fresh impetus to the sluggish Korean economy , saying it will create 300,000 jobs . But the opposition has promised to fight the FTA until the beef pact is nullified . In 2003 , the United States exported $ 815 million pounds of beef and beef variety meats to South Korea . The U.S. beef industry has lost up to $ 4 billion since the market closed , according to the U.S. Meat Export Federation .
U.S. to open market to most U.S. beef says government official . Ban began in October 2007 amid concerns over a case of mad cow disease in the U.S. New agreement bans the import of high-risk materials , like tonsils and brains . thousands of South Korean have regularly staged protests against South Korea beef imports .