The veal shipment that arrived in January containing banned spinal cords was an isolated incident and "does not indicate weakness in the overall U.S. beef processing, inspection or export systems," the U.S. Department of Agriculture said in a report released Monday.

The report, which blames the error on bad communications, was compiled in response to questions submitted by Japan. But experts said that assurances alone won't be enough to win back consumer trust in American beef, and Japan is likely to continue its import ban.

"Japan distrusts U.S. beef. To overcome consumer distrust, the U.S. needs to put in checks and checks and more checks to minimize the risk of human error," said Kiyotoshi Kaneko, professor of physiology at Tokyo Medical University. "The new measures fall short."