Japanese Prime Minister Fumio Kishida visited the earthquake-hit central region on Sunday and promised further help for survivors.

Kishida visited emergency shelters in Ishikawa prefecture to speak with disaster victims who fled their homes after a 7.5-magnitude quake on New Year's Day and powerful aftershocks that killed at least 221 people.

"I realise tough times are continuing. I received your thoughts and I will continue to do my part with all of my strength. Please stay strong," he told a group of survivors who were staying at a middle school in Wajima city.

After the initial jolt, the region has been hit by a tsunami and well over 1,000 aftershocks, some of them registering above 5.0-magnitude, that flattened houses and wrecked infrastructure.

Two weeks since the disaster struck, more than 20,000 residents in the remote region continue to live in nearly 400 shelters.

Hundreds of people are also in more than a dozen communities that cannot be accessed by vehicles after the quakes damaged roads and caused landslides.

Some 9,300 households remain without power.

Quake survivors told Kishida about their reservations about moving away from their hometowns, where their jobs and houses are.

Local officials also told him about public health worries such as spread of infectious diseases like Covid and influenza at congested shelters and urged the national government to quickly build more prefabricated homes to house local residents.

Officials also stressed that many survivors left their homes as they were with no money, change of clothes or other belongings.

After his visit, Kishida pledged to release more than 100 billion yen ($690 million) from the government's reserve fund to help the region before the end of January.

"Many survivors told me about their frustration and anxiety about their uncertain future," Kishida told reporters.

"I am resolved to give all my strength to deal with the disaster and to restore the lives of the survivors."