The March 11, 2011, earthquake and tsunami triggered the worst nuclear accident since Chernobyl at Tokyo Electric Power Co's Fukushima Daiichi plant, 220km northeast of Tokyo.

The natural disasters and meltdowns at the Fukushima plant forced hundreds of thousands of residents to flee their homes.

Japan's Chief Cabinet Secretary Yoshihide Suga on Wednesday lauded the recovery efforts underway in Japan's northeast but acknowledged the challenges that remained in providing psychological care and other services to evacuees.

Prime Minister Shinzo Abe will hold a small memorial ceremony in the afternoon and observe a moment of silence at the time the 2011 disaster struck.

"I think there were other ways to handle (the memorial)," said Natsumi Hoshi, a 42-year old Tokyo resident, who was among a group of people gathered in a city park to lay flowers.

"I think people are still hurting," he said.

Despite the many signs of recovery in Japan's northeast, some residents are still unable to live in the areas closest to the Fukushima plant. Radiation levels in such areas remain high despite repeated decontamination efforts.

The government called off a memorial event that was scheduled for Wednesday as Japan sought to contain a widening outbreak of the coronavirus.

The country has closed schools, theme parks and zoos, as part of its wider effort to scale back public events and mass gatherings to slow the transmission of the virus.

Japan has nearly 1300 cases, including about 700 from the Diamond Princess cruise ship that was quarantined near Tokyo last month. The virus has infected more than 111,000 people and killed more than 4000 globally.

Australian Associated Press