The United States was pushing South Korea on Monday to overturn its ban on American beef, as Seoul weighed its mad cow disease fears against the benefits of a wider bilateral free-trade agreement. A South Korean Agriculture Ministry official said the second day of beef talks had started but declined to give further details, citing the ongoing negotiations. He asked not to be named because he was not authorized to speak to the media. During the first day of talks Friday, the US pressed South Korea to open its market to American beef imports, but Seoul insisted it would make a decision on Washington's demand only after discussing the issue with experts. The US says a resolution of the beef dispute is needed for congressional leaders in Washington to support a wider free-trade agreement with South Korea that was signed last year. South Korea was the third-largest foreign market for American beef before it banned imports in December 2003 after the brain-wasting disease was discovered in the US.