On the same day Canada told its citizens to stay 80 kilometres away from Japan's damaged nuclear power plant, Ottawa announced it is sending two buses to help Canadians evacuate that area.

The Foreign Affairs Department said Thursday in a statement that buses had been chartered and would be used to help Canadians and other foreign nationals, beginning Friday morning.

"The Emergency Operations Centre in Ottawa has been contacting Canadians in the affected areas who registered with our Registration of Canadians Abroad service to advise them of the availability of bus transportation," said the statement.

The two buses will leave Sendai City Hall at about 11:00 a.m. local time Friday morning, DFAIT said.

"Priority will be given to Canadian citizens and their immediate family. Permanent residents are also eligible," DFAIT spokesperson Claude Rochon said in an email.

Passengers will be removed from the area surrounding the Fukoshima Dai-ichi nuclear power plant and taken to Tokyo.

There are about 200 registered Canadians in the area affected by the earthquake and nuclear disaster. Sixteen have already been removed by buses chartered by other counties. Some Canadians who have family and friends in the area have told officials they don't want to relocate.

• Canadians interested in boarding one of the buses should call the Canadian embassy in Tokyo: 81-3-5412-6200, or the Emergency Operations Centre in Ottawa: 613-944-2471 or 613-943-1055.

Passengers can take one piece of luggage and there will be no cost for the service, DFAIT said. Pets are not allowed.

Earlier Thursday, Ottawa warned Canadians to stay at least 80 kilometres from Japan's Fukoshima Dai-ichi nuclear power plant -- an advisory that came as many countries and organizations worked to evacuate their citizens from at-risk areas.

Ottawa has already warned against non-essential travel to Japan, but updated the advisory late Wednesday to include the 80-kilometre radius warning for those who are in the country.

The Foreign Affairs Department has also said Canadians in Tokyo and other affected areas should consider leaving.

The U.S. has also warned that the evacuation zone around the plant should be extended to 80 kilometres, with a top nuclear official warning that meltdown is not far away. Britain also implemented the 80-kilometre warning on Thursday.

Japan has evacuated all residents who live within a 20-kilometre radius of the crippled plant, and has told those between 20 and 30 kilometres to either leave or stay sealed indoors.

Many have also left Tokyo, a metropolitan area with a population of 35 million which is 270 kilometres away from the power plant.

Airports around Tokyo were jammed Thursday with travellers attempting to leave the region.

Many are moving to the south or southwest, including Osaka, where many foreign journalists and some foreign embassies have temporarily located.

Michael Wade Donnelly, the founder of the University of Toronto's Asian Institute, said the Japanese government is "notoriously prudent, cautious, careful and slow moving," and has not yet advised anyone to leave Tokyo.

"People are doing this on their own," he told CTV's Canada AM.

"They're contacting friends and family, they're looking desperately for shelter but my impression watching the television day in and day out is a lot of this is families and individuals doing this on their own."

The governments of a growing number of nations -- including Australia, Britain, Germany, Italy and the Netherlands, New Zealand and South Korea -- have advised their nationals to steer clear of Tokyo and areas to the north.

Chinese evacuations, criticism

Since China began evacuating its nationals from the region on Tuesday, it has reportedly moved more than 3,000 people from the hard-hit prefectures of Miyagi, Fukushima and Iwate to Niigata on Japan's west coast.

"We hope that Japan tells the world what is happening on the site in a timely and accurate manner as well as their evaluation of and predictions for the situation as it develops," Chinese Foreign Ministry spokesperson Jiang Yu said at a press briefing Thursday.

"China and Japan are both members of the International Atomic Energy Agency. According to international treaties, Japan has an obligation to report relevant details to the IAEA and then the IAEA will inform its other members," she said.

Watching developments in Osaka, CTV's Tom Walters said the Chinese comments speak, "to a growing concern that there's a credibility gap here in the information coming out about this incident.

"There is definitely some rising alarm that we are not hearing everything," he told CTV's Canada AM.

While China calls on the Japanese government to be more forthright in disclosing exactly what is happening at the Fukushima nuclear plant, other governments have avoided overt criticism.

Britain's Foreign and Commonwealth Office, for example, said in a statement it had no argument with the Japanese risk assessment.

"For those outside the exclusion zone set up by the Japanese authorities there is no real human health issue that people should be concerned about," the ministry said in its latest travel advisory for Japan.

"Due to the evolving situation at the Fukushima nuclear facility and potential disruptions to the supply of goods, transport, communications, power and other infrastructure, British nationals currently in Tokyo and to the north of Tokyo should consider leaving the area," it said. Any Britons choosing to stay are also advised keep at least 80 kilometres from the plant.