"We look forward to the next two days of technical discussion," John Clifford, the US Agriculture Department's chief veterinarian, said at the start of the meeting.
Tokyo banned American beef in December 2003 after the first case of mad cow disease in the United States.
The ban has since been relaxed, but Japan currently only allows imports of US beef from cattle aged 20 months or younger. This restriction has greatly reduced the volume of beef eligible for shipment to Japan, once the top US export market.
Washington wants Tokyo to raise the ceiling to allow beef from cattle aged up to 30 months, in line with global standards.
The meeting is widely seen as the start of a process to review the safety rules, although Japanese officials say that relaxing current guidelines should not be seen as something that has already been decided.
A farm ministry official said that the purpose of the meetings was to hear what safety measures the United States is taking, including its policy on feed suspected of spreading the brain-wasting disease.
He said officials would have to see how meetings progress before Tokyo decides whether to take the review process further.
Food safety is crucial for Japan, and Tokyo was not immediately thinking of relaxing beef import conditions, he said. (Reuters)
