Farm chief Yoshiyuki Kamei on Sunday called a U.S. probe into the outbreak of mad cow disease incomplete and said Japan will not reconsider the ban on American beef until it receives new proposals for tighter safeguards.

Kamei said he asked the most recent U.S. delegation, led by Trade Representative Robert Zoellick, to propose safeguards "based on" Japan's system, which Kamei credited with restoring consumer confidence in domestic beef.

"We have explained our country's position to (Zoellick) and other U.S. officials," Kamei said in a television interview. "We are expecting some kind of proposal from the United States."