The evacuation of Chinese citizens from areas in Japan worst hit by the quake, tsunami and subsequent damage to nuclear reactors, is being organized, the Chinese embassy in Tokyo said on Tuesday.

The evacuation plan was announced as China's nuclear safety agency said on Tuesday it was "closely monitoring" developments in Japan.

The embassy said it was organizing the evacuation "owing to the seriousness and uncertainty surrounding the accident at the Fukushima Daiichi nuclear plant".

The embassy was preparing to send buses to evacuate Chinese citizens from the cities of Fukushima, Miyagi and Ibaraki, the China News Service said. It said they would be transported to airports to fly back to China, but gave no indication how many people will be involved or any other details.

The number of Chinese citizens living in Japan's northeast is unclear.

Many Chinese people living in Japan work in factories, and the area around Fukushima is home to numerous small manufacturers.

Although the crisis deepened, China is confident that Japan can overcome the adversity, the Foreign Ministry said on Tuesday.

"We are confident that they will be able to overcome these hardships, and China will provide more aid based on the needs of Japan," spokeswoman Jiang Yu told reporters during a regular news briefing.

China also expressed sympathies to Japan and offered help in relief efforts.

Both President Hu Jintao and Premier Wen Jiabao offered condolences on Monday to victims of the disaster.

In a message to Japanese Emperor Akihito, Hu pledged to offer as much help as necessary. Hu also expressed the hope that the Japanese people could overcome their difficulties and rebuild their lives as soon as possible.

The Ministry of Defense said on Tuesday the country's military is willing to offer quake-relief materials and rescue teams to Japan.

Apart from relief materials, the armed forces could also send medical, rescue, or disease prevention teams or a hospital ship to the quake zone as soon as possible, it said in a statement.

Defense Minister Liang Guanglie expressed willingness to offer help on Friday.

Foreign Minister Yang Jiechi met with Japanese Ambassador to China Niwa Uichiro in Beijing on Monday to offer continued support for disaster relief work.

China has sent a 15-member rescue team to Japan, and the Ministry of Commerce has donated 30 million yuan ($4.58 million) worth of emergency assistance.

China's Red Cross Society on Tuesday donated 5 million yuan in emergency aid to its Japanese counterpart, in addition to the 1 million yuan it donated on Saturday.

China's coast guard said it has a cutter on standby to help with Japan's relief operations.

If requested by Japan, the mission would mark the Chinese coast guard's first-ever participation in an international relief effort.