Chief government spokesman Yukio Edano said Tokyo had ordered the suspension of shipments of milk and certain vegetables, including spinach, from regions near the plant.

But Edano downplayed risks, saying that "even if you eat and drink them several times, they will not constitute a health hazard."

According to the Xinhua News Agency, China's quality watchdog said Monday that it has asked local authorities to monitor food imported from Japan for radiation.

A World Bank report Monday put the figure at closer to $235 billion, still making the natural disaster one of the most expensive in modern history.

"While it is too early to estimate accurately, the cost of the damage is likely to be greater than the damage caused by the 6.9-magnitude Kobe earthquake in 1995," the World Bank concluded.

The tourism industry in Japan has also collapsed and is not likely to soon recover.

As of Monday, when the last Chinese tourist group to Japan landed home, all groups of tourists had returned safely, according to the National Tourism Administration.

Ge Lei, marketing director for China Youth Travel Service, told the Global Times that his company has canceled all trips to Japan for March and April, usually a prime season for seeing cherry blossoms.

"It's a big blow to our market, as Japan is one of the major routes at this season. Up to 800 customers canceled their trips until the end of April. This is without counting the impact on neighboring markets such as South Korea," Ge said.

Separately, the US State Department said Monday that it was making potassium iodide available to US government workers and their dependents located in the vicinity of the Fukushima plant.

This is "a precautionary measure for US government personnel and dependents" in Nagoya, Tokyo, Yokohama and 15 prefectures "out of an abundance of caution," the department said in a travel warning, adding that iodide should be consumed only upon receiving specific instructions from the government.