ISHINOMAKI (Japan) (AFP) - Japan on Monday marked the second anniversary of a ferocious tsunami that claimed nearly 19,000 lives and sparked the worst nuclear accident in a generation.

The government will host a national ceremony in Tokyo, attended by Emperor Akihito and Empress Michiko, to mourn 15,881 people who died and 2,668 others who remain unaccounted for.

They and the rest of the nation will observe a moment of silence, the moment a 9.0-magnitude earthquake struck on March 11, 2011, in waters off the northeastern Pacific coast.

The jolt unleashed a killer tsunami that swallowed coastal communities and battered the Fukushima No. 1 nuclear plant, which went through meltdowns and explosions in what was to become the worst nuclear accident since Chernobyl in 1986.

Efforts to rebuild the disaster-hit region have been slow. Figures show 315,196 people are still without a permanent home, many in cramped temporary housing units.

"Unless spring comes to the Tohoku region, a real spring won't come to Japan. We are determined to accelerate reconstruction work," Prime Minister Shinzo Abe said in video posted on YouTube Monday, referring to Japan's northern region devastated by the disaster.

Tsunami-hit communities are divided among those who want to rebuild on land that may have been in the family for generations and those who want to move their town to higher, safer ground.

Complications associated with stressful living conditions have killed 2,303 survivors of the quake-tsunami, government figures show, while domestic violence and depression are increasingly noted as problems in some communities.

Anti-nuclear campaigners Greenpeace say the government has failed to provide enough support to people who fled the radiation, saying some are "in financial ruin and divorces and mental breakdowns are mounting".