SEOUL, South Korea (AP) -- South Korea agreed to resume U.S. beef imports that had been halted over mad cow disease, clearing a key hurdle to a broader trade deal with Washington just hours before the countries' leaders were to meet Friday.
South Korea suspended U.S. beef imports in 2003 after mad cow disease was discovered in the United States, cutting off what was then the third-largest market for American beef.
Restricted imports resumed last April, but have been on hold since October when a shipment contained animal parts that have been banned over mad cow concerns.
The beef issue has been a major irritant in relations between the allies, and threatened prospects for approving a wider free-trade agreement --one of the main agenda items at a summit starting Friday in Washington between South Korean President Lee Myung-bak and President Bush.
Although not directly related to the free-trade pact, some U.S. lawmakers had insisted the beef issue needed to be resolved for them to back the deal. Legislatures in both countries have yet to approve the pact that was negotiated last year.
South Korea's Agriculture Ministry said Friday that revived imports were expected to begin in mid-May and expand in stages.
Seoul will first allow American beef imports from cattle younger than 30 months, including cuts with bones. Younger cows are believed to be less at risk for mad cow disease.
Beef from older cattle will also be cleared for imports after the U.S. strengthens controls on feed to reduce chances of infection, the ministry said.
South Korea's chief negotiator Min Dong-seok said the U.S. had agreed to press for the feed measures, adding that resolving the beef issue would help strengthen ties between the two countries.
''The beef issue has been a factor that caused distrust between South Korea and the U.S,'' Min told reporters.
Seoul also agreed not to immediately halt imports even if a new case of mad cow disease is discovered in the U.S., Min said. Instead, Seoul would only move to halt imports if the Paris-based World Organization for Animal Health downgrades its safety rating for American cattle.
That organization had determined last year that the U.S. was a ''controlled risk nation,'' a category that means countries can export beef regardless of the animal's age _ adding to pressure on Seoul to lift its import ban.
Scientists believe mad cow disease, or bovine spongiform encephalopathy, spreads when farmers feed cattle recycled meat and bones from infected animals. Eating meat from infected animals is also believed to be linked to the rare but fatal brain-wasting human variant, Creutzfeldt-Jakob disease.
South Korean farmers have vigorously opposed the free-trade deal with the U.S., fearing cheaper imports will threaten their livelihoods.
About 30 farmers and activists protested outside the agriculture ministry shouting, ''Mad cow, mad government! Our people are getting mad,'' as several hundred riot police stood watch.