All other food products produced or manufactured in the prefectures Fukushima, Ibaraki, Tochigi and Gunma would be diverted for testing, according to the spokesperson. The spokesperson added that food products from other parts of Japan would undergo tests as resources allow, but the FDA is mainly focused on food from these four areas.

The Fukushima Daiichi nuclear power plant was extensively damaged by the earthquake and tsunami that hit Japan on March 11. Meanwhile, efforts are on to bring the plant's cooling systems back online and stabilize the situation.

Several food products have already been officially off the shelf in domestic and export markets. Japanese prime minister Naoto Kan had previously ordered the governors of these four prefectures to halt the distribution of spinach and the local vegetable kakina. He had also told the governor of Fukushima to halt all raw milk distribution, according to the FDA.

The FDA would continue to flag all entries from Japan to determine if their origin was within the affected area, according to the spokesperson.

At four locations in Fukushima, milk was found to contain levels of radioactive iodine ranging around 20% over the acceptable limit to more than 17 times that limit according to Japanese officials. Tests at one location also revealed levels of cesium about 5% over the acceptable limit, the health ministry reported.

Moreover, in Ibaraki, a major center of vegetable production, tests at 10 locations revealed iodine levels in spinach ranging from over 5% over acceptable limits to exceeding 27 times that ceiling. At seven sites, levels of cesium was measured at 4% to nearly four times the limit.

The U.S. only imports 4% of food from Japan in general.

Meanwhile, Japan's chief cabinet secretary said consuming the affected milk and spinach every day for a year would translate to taking in the same amount of radiation as a single CT scan.

From the April 4, 2011, Prepared Foods E-dition