South Korean millers said on Friday they would suspend imports of U.S. wheat until the results of tests by the Asian nation's government on whether shipments have been tainted by an unapproved genetically modified strain of the crop.
Major buyer Japan has already shelved plans to purchase U.S. wheat and other Asian countries say they are monitoring the situation, while the Europe Union will step up testing.
U.S. officials have been racing to quell alarm following news that the strain, developed by biotech giant Monsanto Co , was found in an Oregon field late last month.
South Korea imported 1.2 million tonnes of wheat for food from the United States last year, with the same amount for animal feed.
The results of the tests by Korea's Ministry of Food and Drug Safety are expected in the first week of June.
The ministry said that it had received the information on the GM wheat from the U.S. via its Seoul embassy on May 29 ahead of the broader U.S. announcement.
The Korean agriculture ministry has said separately that it would heighten quarantine measures on U.S. feed wheat.
