The International Atomic Energy Agency (IAEA) said on Wednesday that there are some positive developments related to the availability of electrical power supply to Japan' s stricken nuclear power plant, but "overall situation remains of serious concern."

Efforts to spray water into the No. 4 reactor at the Fukushima Daiichi Nuclear Power Plant, which was struck by an earthquake and tsunami in Tomioka, Fukushima Prefecture, northeastern Japan, are seen in this March 22, 2011 handout photograph released by Tokyo Electric Power Co.  Power has been reconnected to all the six reactors at Japan's troubled Fukushima Daiichi nuclear power plant and the lighting in the control room for the No. 3 reactor was restored on Tuesday. (Xinhua/Reuters Photo)

"As a positive development, instrumentation, as it becomes available, is providing more data that can be assessed by experts, " Andrew said.

However, he said pressure readings in Unit 2 appear to be less reliable, and only limited data is available concerning the reactor pressure vessel and reactor containment vessels' integrity of this unit.

In addition, temperature readings in the reactor pressure vessels of Units 1 and 3 were high and of some concern.

Andrew said the second IAEA monitoring team has arrived in Japan to strengthen the team already in the country.

On the matter of seawaters near the Fukushima plant being contaminated, Andrew said monitoring data from Japanese authorities will be assessed by IAEA experts from the agency's Marine Environment Laboratory, Monaco.

Japanese officials will continue to provide IAEA with information about the presence of radioactivity in milk, drinking water and vegetables in some areas.

IAEA, together with the Food and Agriculture Organization (FAO), and the World Health Organization (WHO), have issued a joint statement, vowing to mobilize their knowledge and expertise in support of the Japanese government's efforts to address food safety issues.

VietNamNet/Xinhuanet