Blanket testing for mad cow disease will continue for the time being, even though the government admitted last week that the approach has some technical limitations, a senior farm ministry official said Monday.

Mamoru Ishihara, vice minister of agriculture, forestry and fisheries, claimed that stopping the tests merely because of the limitations would be problematic.

During three days of talks with the United States in Colorado, Japan acknowledged for the first time that blanket screening has shortcomings in terms of detecting whether young cows have been infected with the brain-wasting disease.

This is a view that the United States has pushed all along.

Japan will not immediately change its policy of testing all slaughtered cattle, however, as there is no established theory yet for detecting the disease, according to Ishihara.

"There is not enough scientific data on BSE," Ishihara told a news conference.

He also stated that blanket testing may become more important in future. Japan has been conducting blanket tests since the country experienced its first outbreak of the disease in 2001.

Japan and the United States have been at loggerheads over a system for detecting the disease, technically known as bovine spongiform encephalopathy.

Japan has called for blanket tests as a precondition for reopening its market to American beef, while the United States has rejected this demand, saying it has no scientific basis.