Japanese Prime Minister Naoto Kan and visiting French President Nicolas Sarkozy defended the use of nuclear power despite the ongoing nuclear crisis in Japan on Tuesday.

French President Nicolas Sarkozy (L) is welcomed by Japanese Prime Minister Naoto Kan prior to their talks at Kan's official residence in Tokyo March 31, 2011. [Xinhua]

At a joint press conference, Kan and Sarkozy called for the Group of 20 nations to meet and discuss the revision of international nuclear safety standards.

"We will ask the nuclear safety authorities of the Group of 20 countries to meet, if possible, in Paris during May, to define international nuclear safety standards," the French leader said at?the press conference.

Both leaders also agreed that the nuclear issues will be the top agenda of the Summit meeting between the Group of Eight industrial nations, which will be held in late May.

The Japanese Ministry of Health, Labor and Welfare said Tuesday that radioactive substance exceeding the legal limit has been detected in beef in Tenei, Fukushima Prefecture.

The ministry said that 510 becquerels of radioactive cesium was found in beef from Tenei, above the 500-becquerel legal limit set under the food sanitation law, Kyodo reported.

The Nuclear and Industrial Safety Agency said radioactive material about 10,000 times the legal limit was found at the groundwater and the level of radioactive iodine-131 in seawater was 4,385 times the legal limit near the crippled Fukushima nuclear power plant.

The International Atomic Energy Agency (IAEA) and the enviromental group Greenpeace both claimed that radiation at the Iitate village outside the evacuation zone has surpassed the recommended level and called on the Japanese government to expand the evacuation zone.?

But the Japanese authorities Tuesday rejected those calls to expand the the 20-km evacuation?area around the paralyzed nuclear power plant, Xinhua reported.

"We have no plans to immediately evacuate people, but naturally, high radiation levels in soil, if continued over a long period of time ... if need be, (we will) take steps to deal with it," Chief Cabinet Secretary Yukio Edano said Thursday.