Kan visited Ishinomaki, a coastal city of 163,000 people in Miyagi, one of the prefectures (states) hardest hit by the March 11 earthquake and tsunami that killed as many as 25,000 people, destroyed miles of coastline and left tens of thousands homeless.
Ishinomaki Mayor Hiroshi Kameyama told him the government needs to quickly build temporary homes for the 17,000 city residents who lost theirs and are living in shelters. More than 2,600 people from Ishinomaki were killed in the disaster and another 2,800 are missing. Boats were also destroyed, crippling the fishing industry that accounts for 40 percent of the city's economy.
While Kan was visiting Ishinomaki, Japanese and U.S. troops fanned out along the coast in another all-out search for bodies by land, air and sea.
Television news showed them using heavy equipment to lift a boat washed inland by the tsunami so they could search a crushed car underneath. No one was inside.
"A month after the earthquake and tsunami, many people are still missing," said Japanese defense ministry spokesman Norikazu Muratani. "We would like to do our utmost to find bodies for their families."
Only 13,000 deaths have been confirmed so far, and many bodies have likely washed out to sea and will never be found.
A similar three-day search with even more troops a week ago found just 70 bodies, underscoring the difficulties of locating victims in the ocean and the debris along the coast.
In coastal Fukushima on Sunday, a middle-aged man watched as soldiers in scuba gear dove underwater. He hoped they would locate his younger brother, a fisherman who was swept away.
"He must be trapped in the boat," the man told public broadcaster NHK, which did not identify him. "I'm just praying soldiers will find him."
The latest search was to last just one day and did not include the 12-mile (20-kilometer) evacuation zone around the tsunami-flooded Fukushima Dai-ichi nuclear complex. Police officers decked out in full protective gear continue the dangerous, painstaking task of looking for bodies inside that zone.
Workers at the complex have spent the past month frantically trying to stop radiation spewing from nuclear reactors by restoring the cooling systems, but they still have a long way to go.
Contamination in water pooling around the complex has slowed efforts to stabilize the reactors, emitting so much radiation in some places that workers can get in only for short periods of time, if at all.
In a move that prompted some criticism from neighboring countries, engineers decided earlier this month to deliberately pump less-contaminated water into the ocean from a storage facility they thought might make a good receptacle for the more highly radioactive water. They are also pumping out water from drains to keep it from backing up.
"I would like to apologize from my heart over the worries and troubles we are causing for society due to the release of radiological materials into the atmosphere and seawater," Sakae Muto, a vice president of the nuclear plant's operator, Tokyo Electric Power Co., said Saturday.
The pumping was set to end Sunday, and officials hoped that within days they could start transferring the more highly contaminated water to the now-drained facility. The operation is risky because the water will be transferred through a hose snaking around the complex, meaning that if there are cracks or leaks in the hose, radiation could escape.
"We must make sure we can do this safely," said Hidehiko Nishiyama, chief spokesman for Japan's nuclear safety agency.
Now that removal of the contaminated water is under way, officials are starting to consider options for restoring cooling systems vital to preventing further reactor damage. But they won't know what will work best until the water is out of the way and they can see which parts are usable and which have been destroyed.
"We are not opting for entombment at the moment," said spokesman Junichi Matsumoto. "We see that Units 1-4 reactors are relatively stabilized, judging from the reactor temperature and water level, while we are short of calling them stable."
Engineers have struggled to get data from the reactors because they don't have normal access to them. On Sunday, a tiny remote-controlled drone aircraft from Honeywell did its first flight around the compound. Eventually, the gadget may be able to provide more specific information on radiation and temperatures in areas that have been off-limits to workers.
Meanwhile, in Tokyo's Koenji section, where many students live, thousands of people carrying "No nukes" signs gathered for a rally in a park Sunday, then marched through the streets chanting and beating drums. Elsewhere in Tokyo, about 140 miles (220 kilometers) southwest of Fukushima Dai-ichi, protesters demanding the closure of a different plant chanted "No more Fukushima" as they marched through government headquarters and past the Nuclear and Industrial Safety Agency.
Associated Press writer Mayumi Saito and television news producer Miles Edelsten contributed to this report.