WASHINGTON — Japan has suspended some imports of wheat from the United States after genetically engineered wheat was found on an Oregon farm.

The Agriculture Department announced the discovery on Wednesday. No genetically engineered wheat has been approved for American farming.

Japan is one of the largest export markets for American wheat growers. Katsuhiro Saka, a counselor at the Japanese Embassy in Washington, said Thursday that Japan had canceled orders of western white wheat from the Pacific Northwest and also of some feed-grade wheat.

“In most countries the unapproved genetically modified wheat would be a target of concern,” Mr. Saka said. “The Japanese people have similar kinds of concerns.”