Japan on Sunday marked six months since an earthquake and tsunamidevastated its north-east coast, amid pessimism about the recovery effort and anxiety over radiation leaks from the Fukushima Daiichi nuclear power plant.

Across the region hit by the disaster, people bowed their heads in silence at 2:46 pm, the moment a magnitude-9 earthquake – the biggest in Japan’s recorded history – struck, setting off a tsunami that would leave about 20,000 people dead or missing, and trigger the world’s worst nuclear accident for 25 years.

The tsunami damaged or destroyed 80,000 homes and disrupted supply lines to key industries, while the nuclear crisis spread radiation over large areas and forced the evacuation of about 100,000 people living in or near a 20-kilometre exclusion zone around the plant.

The recovery effort is expected to take years to complete at a cost of hundreds of billions of dollars. So far, only four of the 31 communities worst affected by the disaster have completed draft reconstruction plans.

On Saturday, Japan’s new prime minister, Yoshihiko Noda, made his first visit to the tsunami disaster zone, promising local leaders he would speed up the reconstruction effort.

Despite progress in rehousing an estimated 400,000 displaced people and clearing millions of tonnes of debris, many survivors say they face a bleak future.

According to a survey by the public broadcaster NHK, 158,000 people lost their jobs in the three hardest-hit prefectures of Iwate, Miyagi and Fukushima. Half of those surveyed said they had no prospect of finding work or would lose their incomes within a year.

The Red Cross said Japanese bureaucracy had delayed the provision of assistance to victims. “The speed and scope of implementing the response during the emergency phase was not as swift and comprehensive as [we] wished, partly due to the structure of disaster management in Japan, partly because of insufficient preparedness,” it said in a report.

Noda, Japan’s seventh prime minister in five years , is dealing with the first crisis of his administration with the resignation of his trade and industry minister, who described the area near Fukushima Daiichi as “towns of death”.

Yoshio Hachiro, who had been in the post for just over a week, apologised for the remark, made after a visit to areas near Fukushima Daiichi that have been declared no-go zones. He added: “You can’t find a place like that anywhere. I couldn’t think of any other way to describe it.”

Hachiro’s fate was sealed on Saturday after newspaper reports that he had also pretended to rub his sleeve against a journalist while joking that he might be contaminated with radiation.

Noda, who took office vowing to bring stability to Japanese politics, said: “I apologise deeply to the people of Fukushima, who have had their feelings badly hurt. I continue to believe that without a revival in Fukushima, there will be no revival of Japan.”

Last month the government warned that dangerously high radiation levels could make areas near the plant unfit for human habitation for years, possibly decades.