Rebuilding Japan's devastated towns and cities may take a decade, Reuters reported on Wednesday.

"The first three years would be needed for tasks like rebuilding roads and constructing temporary housing," Jun Iio of Japan's Reconstruction Design Council, formed after the quake to advise the government's rebuilding efforts, said.

Iio, a political science professor, told reporters an additional four years would be necessary to rebuild towns. Full recovery could take even longer.

Referring to the Japanese city ravaged by a powerful earthquake in 1995, Iio said, "We have to bear in mind that the area afflicted by the disaster is much larger than Kobe."

The reconstruction council also said the challenges of rebuilding after the March disaster have been made greater by a crisis at the tsunami-stricken Fukushima nuclear power plant.

The devastating March 11 Tōhoku  earthquake-tsunami double-header left a large swathe of Japan's northeast in ruins, killed at least 13,000, forced another 130,000 into shelters, and is estimated to have caused $300 billion worth of damage.

Tens of thousands of residents around the Fukushima Daiichi plant have been ordered to evacuate after the tsunami knocked out the plant's cooling functions, leading to leaks in radiation in the world's biggest nuclear disaster since Chernobyl in 1986.

Members of the reconstruction council called for greater regional autonomy to streamline rebuilding and also said the huge work ahead had to transcend political divisions in a country where the fragile political truce inspired by the disaster has collapsed.

"Reconstruction efforts go beyond political issues," said Makoto Iokibe, the council's head and president of Japan's National Defense Academy. "We can invite opinion from opposition parties as well as the ruling party."

Japan's Cabinet last week approved almost $50 billion of initial spending for post-earthquake rebuilding, but ruling and opposition parties are now bickering over how to finance subsequent extra budgets.

Opposition parties, who can block legislation in Japan's divided parliament, have shown little sign of cooperating with Prime Minister Naoto Kan, while lawmakers in Kan's own party are adding pressure on him to resign.

Observers say Kan is unlikely to step down any time soon.