Japan is not satisfied with the U.S. government's plan to step up tests for mad cow disease because it does not meet Japanese demands for blanket testing of all cattle, a top bureaucrat at the farm ministry said Thursday.

Japan will make a decision on whether to resume beef imports from the United States based on the premise that the U.S. government will conduct blanket testing and remove all high-risk materials from cattle, Mamoru Ishihara, vice minister of agriculture, forestry and fisheries, said at a news conference.

"The Japanese position has not changed," Ishihara said.

U.S. Agriculture Secretary Ann Veneman expressed Washington's readiness Tuesday to increase testing for mad cow disease by targeting animals aged 30 months or older.

Japan imposed the import ban on U.S. beef products after the U.S. announced Dec. 23 its first, and only, case of mad cow disease, or bovine spongiform encephalopathy, in a Canadian-born cow in Washington state.

As a condition for resuming U.S. beef imports, Japan has asked the U.S. to test all slaughtered cattle for BSE. The U.S. has rejected the request, saying it is scientifically unreasonable.