Japanese inspectors will start a two-week tour of U.S. meatpacking plants Sunday to check whether beef for export to Japan is being processed safely in compliance with a bilateral agreement, government officials said Friday.

If no problems are found, the plants will move to random checks from the current system in which all beef exports to Japan are checked, they said.

Next week's inspections will cover 27 of the 35 meatpacking plants authorized to export beef to Japan and another plant that is scheduled to receive authorization, according to the officials.

Japan, which banned imports of U.S. beef after the first case of mad cow disease in the United States was discovered in December 2003, resumed imports in December 2005 but reinstated the ban the following month after a shipment violated the agreement for the import resumption. Japan lifted that ban again last July.

U.S. beef exports to Japan have been limited to meat from cattle 20 months or younger as a result of concern that older cattle are likelier to be infected with the disease.

If no safety problems are found during the inspections, Japan and the United States are expected to launch negotiations on upping the age limit.