South Korea has held pork imports from Britain in quarantine. The action follows a Dutch move to ban pig, sheep and goat imports from Britain.

On Wednesday, Britain banned exports of live animals and products after the discovery of the first cases of foot-and-mouth disease in pigs in 20 years.

The United States and the European Union also announced import bans on animal products from Britain.

The United States Department of Agriculture said that pork products that had already arrived from Britain were being quarantined at U.S. ports.

Britain suffered its last outbreak of foot-and-mouth disease in 1981. Since then pig farmers have struggled with low prices, a strong pound and the spread of swine fever last year.