The US has agreed not to export beef to South Korea from cattle older than 30 months in an effort to allay South Korean concerns over meat safety.
Both sides say the deal was reached during talks in Washington between top South Korean and US trade officials.
South Korea used to be a major market for US beef, but suspended imports in 2003 after a case of "mad cow disease" was identified there.
Seoul's decision in April to end the suspension...
Three men have reportedly posed as terrorists and tried to extort more than $300,000 (£150,000).
They have been arrested in the Chinese city of Qingdao.