Tokyo: The United States became the first nation to block produce from ally Japan`s radiation zone, saying it will halt milk, vegetable and fruit imports from areas near the tsunami-smashed nuclear plant because of contamination fears.
The Food and Drug Administration`s decision to stop imports from four Japanese prefectures in the crisis-hit northeast crystallized international anxiety about the impact of the worst atomic crisis since Chernobyl in 1986.
Other nations may follow suit with formal bans. Some private importers have already stopped shipments from Japan anyway.
At the six-reactor Fukushima plant, which was crippled by a March 11 earthquake and tsunami, engineers are battling to cool reactors and contain further contamination.
Showing the widening problem, Japan said on Wednesday above-safety radiation levels had been discovered in 11 types of vegetables from the area, in addition to milk and water.
Officials still insisted, however, that there was no danger to humans and urged the world not to over react.
"We will explain to countries the facts and we hope they will take logical measures based on them," Japan`s chief cabinet secretary Yukio Edano, who has been the government`s public face during the crisis, told a news conference.
The Asian nation`s worst crisis since World War Two has caused an estimated $250 billion damage, sent shock waves through global financial markets, and left nearly 23,000 people dead or missing, mostly from flattened coastal towns.
More than a quarter of a million people are living in shelters, while rescuers and sniffer dogs comb debris and mud looking for corpses and personal momentous.
Worsened by widespread ignorance of the technicalities of radiation, public concern is rising around the world and radioactive particles have been found as far away as Iceland.
Japan has already halted shipment of some food from the area and told people in the area to stop eating leafy vegetables.
Asian neighbors are inspecting imports for contamination, and Taiwan advised boats to stop fishing in Japanese waters.
Vienna-based U.N. watchdog, the International Atomic Energy Agency (IAEA), expressed concern about a lack of information from Japanese authorities. It cited missing data on temperatures of spent fuel pools at the facility`s reactors 1, 3 and 4.
"We continue to see radiation coming from the site ... and the question is where exactly is that coming from?" added a senior IAEA official James Lyons.
Although there has been progress in restoring power to the Fukushima site 13 days after the accident, plant operator Tokyo Electric Power Co (TEPCO) said it needed more time before it could say the reactors were stabilized.
Technicians working inside an evacuation zone around the plant, 250 km (150 miles) north of Tokyo, have successfully attached power cables to all six reactors and started a pump at one to cool overheating nuclear fuel rods.
Concern is high over reactor No. 1 after its temperature rose to near 400 degrees Celsius, above a design limit of 302.