An aide to embattled Prime Minister Naoto Kan said the government's priority was to stop radiation leaks which were scaring the public and hindering work on cooling overheated nuclear fuel rods.
"We have not escaped from a crisis situation, but it is somewhat stabilized," said Goshi Hosono, a ruling party lawmaker and aide to Kan.
"How long will it take to achieve (the goal of stopping the radiation leakage)? I think several months would be one target," Hosono said on a nationwide Fuji TV programme on Sunday.
In the face of the prolonged crisis, nearly two-thirds of Japanese voters believe the ruling Democratic Party should join hands with the opposition Liberal Democratic Party (LDP), a Yomiuri newspaper poll showed, potentially warming lawmakers in both camps to the scheme.
Kan last month invited Sadakazu Tanigaki, head of the LDP, to join the cabinet as deputy premier for disaster relief, but Tanigaki rejected the offer.
Plant operator Tokyo Electric Power Co (TEPCO) found a crack in a concrete pit at its No.2 reactor in the Fukushima Daiichi complex at the weekend, generating readings of 1,000 millisieverts of radiation per hour in the air inside.
The leaks did not stop after concrete was poured into the pit, and TEPCO turned to water-absorbent polymers to prevent any more contaminated water from flowing out.
The latest effort to stop radioactive water entering the Pacific started on Sunday afternoon.
"We were hoping the polymers would function like diapers but are yet to see a visible effect," said Hidehiko Nishiyama, a deputy director general of the Nuclear and Industrial Safety Agency.
Officials believe the crack may be one source of the radiation leaks that have hobbled efforts to control the six-reactor complex and sent radiation levels in the sea to 4,000 times the legal limit.
Nishiyama said three of the six reactors were now generally stable. TEPCO has said it will scrap at least four reactors once they are under control, but this could take years or even decades.
Japan's crisis has rocked the nuclear industry and the European Union said on Sunday it will affect the fight against climate change as energy policies are reviewed.
Germany and Switzerland have said they will shut older reactors or suspend approvals, China has suspended approvals for new plants, and Taiwan is studying cutting nuclear output.
PM UNDER PRESSURE
The 9.0 magnitude quake and tsunami on March 11 has left nearly 28,000 people dead or missing and Japan's northeast coast a splintered wreck. The disaster has hit economic production and left a damages bill which may top $300 billion.
After a three day intensive air and sea search by thousands of U.S. and Japanese forces another 77 bodies were recovered, Kyodo news agency said on Sunday.
Prime Minister Kan is under intense pressure to steer Japan through its worst crisis since World War Two, but after three weeks many Japanese are angry that the humanitarian disaster seems to have taken a back seat to the nuclear crisis.
Unpopular and under pressure to quit or call a snap poll before the disaster, Kan has been criticized for his crisis management.
Voter support for the Kan's government stood at 31 percent in the Yomiuri poll, up from 24 percent in the previous survey conducted before the quake.
Still, it also showed almost 70 percent of the respondents believe Kan is not exercising leadership, and 19 percent of them want him to step down soon.
More than 163,710 people are living in shelters, with more than 70,000 people evacuated from a 20 km (12 mile) no-go zone area the nuclear plant, and another 136,000 people living a further 10 km out have been told to leave or stay indoors.
MOVES TO STOP POWER BLACKOUTS
The government estimates damage from the earthquake and tsunami at 16 trillion to 25 trillion yen ($190 billion-$298 billion). The top estimate would make it the world's costliest natural disaster.
Manufacturing in the world's third largest economy has slumped to a two-year low as a result of power outages and quake damage hitting supply chains and production.
General Electric, which helped build the Fukushima Daiichi nuclear power plant will help TEPCO supply electricity in the coming months when demand soars.
Demand for power jumps in Japan in summer due to heavy use of air conditioners. More than 168,500 households in the north are still without electricity after the tsunami.
The government has said it will restrict maximum power use by companies during the hotter months in an effort to avoid further blackouts.
Japan's health ministry said on Sunday it had detected radioactive substances higher than legal limits in mushrooms from Iwaki in Fukushima, said Kyodo.
"Grown in Fukushima" has become a warning label for those nervous of radiation which has already been found in some vegetables close to the nuclear plant.
"There is no way we will be able to sell anything," said 73-year-old farmer Akio Abiko. "People in Tokyo are just too sensitive about this kind of thing."
Milk and other foods such as mushrooms and berries in parts of Ukraine are still contaminated by radioactive fallout from Chernobyl, 25 years after the world's worst nuclear disaster, Greenpeace said on Sunday.