The previously undisclosed hiring of welders from the US and South-east Asia underscores the way Tokyo Electric outsourced its riskiest work.
Chinese Premier Wen Jiabao defended six-party talks proposed by Beijing as the way to defuse volatile divisions on the Korean peninsula.
Engineers at the damaged Fukushima Daiichi plant north of Tokyo said on Sunday they were no closer to restoring the plant’s cooling system.
Japan will pump radioactive water into the sea from a crippled nuclear plant until Sunday, a day later than previously planned.
Japan’s prime minister made his first visit to the country’s tsunami-devastated region on Saturday and entered a nuclear exclusion zone.
Pressure is on Japan to expand the evacuation zone around a stricken nuclear power plant after high levels of radiation were found outside the zone.
Japanese military helicopters dumped water on an overheating nuclear plant on Thursday while the United States expressed growing alarm.
Workers were ordered to withdraw briefly from a stricken Japanese nuclear power plant on Wednesday after radiation levels surged.
Japan faced a potential catastrophe on Tuesday after a nuclear power plant exploded and sent low levels of radiation floating towards Tokyo.
A devastating tsunami triggered by the biggest earthquake on record in Japan on Friday looked set to kill at least 1 000 people.