TOKYO - Japan's Emperor Akihito spoke to the nation Wednesday in the first made-for-TV address of his reign, expressing condolences to victims of the massive earthquake and tsunami and urging the Japanese people not to give up.

Bowing and then speaking solemnly in a gray suit, he also voiced concern about the crisis at a nuclear power plant damaged by the disasters that has led to radiation leakage.

"I am deeply concerned about the nuclear situation because it is unpredictable," he said. "With the help of those involved I hope things will not get worse."

The historic broadcast underscores the gravity of the situation facing Japan. While Akihito makes annual televised speeches to crowds marking the New Year and end of World War II, he has never directly addressed the country on camera, according to the Imperial Household Agency.

Friday's quake-spawned tsunami devastated Japan's northeastern coast, and officials believe more than 10,000 people have died.

Akihito, 77, thanked those involved in disaster relief operations, including foreign governments, and urged an all-out rescue effort.

"We don't know the number of victims, but I pray that every single person can be saved," he said in the roughly six-minute appearance.

Japan faced a worsening nuclear crisis after authorities on Wednesday ordered emergency workers to withdraw from the Fukushima Dai-ichi nuclear power plant amid a surge in radiation, temporarily suspending efforts to cool the facility's overheating reactors.

Radiation levels fell later Wednesday, but it was not immediately clear if the workers had returned, or how far away they had withdrawn. The workers at the forefront of the fight -- a core team of 70 -- had been regularly rotated in and out of the danger zone to minimize their radiation exposure.

Meanwhile, officials in Ibaraki prefecture, just south of Fukushima, said radiation levels were about 300 times normal levels by late morning. While those levels are unhealthy for prolonged periods, they are far from fatal.

The emperor's message was not live but taped earlier in the day, the Imperial Household Agency said.