Workers and volunteers are working hard to clear mud and debris from roads and towns.

The death toll from Japan's worst flooding disaster in 36 years has risen to 200, as authorities continue to search for dozens still missing.

Key points:

• United Nations chief has written to Shinzo Abe to offer condolences and UN support
• Some supermarkets have been forced to close as supplies cut off by flood damage
• Nine-year-old miniature horse found stranded on roof, but returned safe to owners

Heavy rains hit much of western Japan from Thursday last week, with 583 millimetres of rain falling between Friday and Saturday morning alone.

Millions were forced to evacuate due to floods and landslides, with most of the 200 people who have died from the Hiroshima and Okayama prefectures.

After cancelling his trip to Europe and the Middle East to oversee the emergency response, Prime Minister Shinzo Abe visited an evacuation centre in the city of Kurashiki in Okayama prefecture, where more than 40 of the 200 confirmed victims died.

Squatting to talk to an elderly woman sitting on the floor, he pledged to her that his Government will do its utmost to bring her ordinary life back as soon as possible.

Mr Abe listens to an evacuee during his visit to an evacuation centre in Kurashiki.

About 200 residents were taking refuge at the shelter he visited.

"We'll cut through all the bureaucracy to secure the goods people need for their lives, to improve life in the evacuation centres — such as air-conditioners as the hot days continue — and then secure temporary housing and the other things people need to rebuild their lives," Mr Abe said.

Mr Abe is up for re-election as party leader in September and has seen his popularity ratings edge back up after taking a hit over a cronyism scandal earlier this year.

As well as the floods the rains caused devastating landslides.

The United Nations said secretary-general Antonio Guterres had written to Mr Abe offering UN support in the clean-up.

UN spokesman Stephane Dujarric said Mr Guterres expressed his condolences for the loss of life and destruction.

He said the UN chief "commended the Government's efforts to help people affected and expressed his admiration for the domestic search and rescue teams helping those in need".

Residents cut off from supplies

In areas where search-and-rescue operations had ended, construction workers and residents worked in neighbourhoods to clear mud and debris and restore vehicle access to the outside and get supplies and food.

In Hiroshima's Asakita ward, resident Nobuaki Hyuga walked to a neighbourhood convenience store but could only find ice cream and juices, so he had to go further to find bread and other food.

"We are cut off from the road and we can't go anywhere by car," Mr Hyuga said.

Construction worker Fukuyoshi Doi, who is leading a group of volunteers who had gathered to help clear the road, said once they clear the mud "the rest of the work would pick".

"Mud and dirt is still blocking our local bus route, so we are trying to get that out of the way so the road can be reopened for buses and cars," he said.

Delivery companies Sagawa Express Co. and Yamato Transport Co. and cargo service Japan Freight Railway Co. said some of their shipments to and from the flooded areas had been suspended or reduced.

Supermarkets have closed stores or shortened hours due to delivery delays and supply shortages.

Horse rescued from roof

With the torrential downpour coming quick and strong over the weekend, both people and animals looked to higher ground.

Not-for-profit disaster-relief organisation Peace Winds Japan (PJW) tweeted that they found a horse stranded on a roof.

According to The Japan Times, Leaf — a nine-year-old miniature mare — was found on the roof in the Mabicho area of Kurashiki, Okayama Prefecture.

While the group was looking for assistance to help Leaf down, she fell 2 metres from the roof and landed on her torso, the Times said.

Luckily she escaped uninjured and has been reunited with members of the staff at the Mabi Farm where she lived.

Unfortunately her young colt, Earth, was not as lucky and was found dead, according to PJW.