SEOUL – South Korea is asking for a de facto ban on beef from cattle older than 30 months. The request comes after massive near daily protests against a beef trade deal between the United States and South Korea in April.

The South Korean public, driven by fears over mad cow disease, has protested the deal in major cities, filed lawsuits to stop the deal and driven down the approval rating of the country’s president, elected only months ago in a landslide.

South Korea was once one of the largest overseas markets for American beef until bovine spongiform encephalopathy, also known as mad cow disease, was found in a cow in Washington state in 2003. Mad cow disease has been linked to variant Creutzfeldt-Jakob disease (vCJD), a similar disease in humans. In both illnesses, the infectious agent attacks the central nervous system.

After the outbreak, South Korea and other nations banned imports of U.S. beef on concerns of mad cow disease. Late last year, the United States and Canada were certified as controlled risk countries by the World Organization for Animal Health (OIE), saying the countries had control of mad cow disease and meat exports were safe. Since then, the U.S. has been pushing for reopening the beef trade.

In April, the U.S. and South Korea agreed to reopen the market. All beef would be allowed back into the local market, including beef from older cattle, as long as risk materials had been removed. The beef deal was also seen as necessary for the approval of a free trade agreement between the two countries even though it had not been part of negotiations for the FTA.

Since the agreement was signed on April 18, the South Korean public has protested deal, demanding a renegotiation of the deal. In recent weeks, including one protest of 60,000, people have marched on the capital with Korean news agencies and the Associated Press reporting clashes between protestors and police. Implementation of the deal, scheduled to start this week, has been delayed because of the protests.

South Korean Agriculture Minister Chung Woon-chun, told Korea’s Yonhap News Agency, that quarantine inspections would not happen for U.S. beef imports until public confidence in the government is restored. South Korean President Lee Myung-bak currently has a 20 percent approval rating.

Major U.S. beef producers such as Tyson Foods Inc., Cargill Meat Solutions Corp., Smithfield Beef, National Beef Packing and JBS Swift have already announced a temporary labeling program for beef products that come from cattle more than 30 months old. The companies said in a joint release this week that the labels would be in use for 120 days. Most beef processed by the companies comes from cattle less than 30 months old.

That has not stopped protests, including 1,000 people gathering in Seoul on Friday. Another 25,000 had protested on Thursday.

According to Yonhap, a government source said Seoul is trying to resolve the impasse by using the private sector, since revising a signed agreement is very difficult and could lead to diplomatic complications and trade friction, in the worst case scenario.

Both countries have said that renegotiation of the deal is not an option.

The FTA, already passed by the U.S. Congress, has not been approved by the South Korean National Assembly because of opposition parties’ objection to the beef deal.

At this time, there has been no sign of change with the South Korean caught between diplomatic obligations and the public. The ruling party has already suffered losses in local elections because of the public anger over the beef deal.