Japan did not set a date Friday for lifting its import ban on U.S. beef in a report it submitted to the Office of the U.S. Trade Representative in reaction to the USTR's call for an early resumption of imports.

"Japan cannot predict a specific time frame of the resumption at this juncture of the review" of domestic steps to detect mad cow disease, the report says. "This is not a trade issue, but a food safety issue," Japan said, stressing the need for food safety and consumer confidence "as a prerequisite as well as based on science."

The beef issue has been at the center of a bilateral dispute.