Japanese Prime Minister Yoshihiko Noda says reforming the debt and disaster-stricken country's social security and tax system is the most important item on his 2012 legislative agenda.

Speaking at a news conference Wednesday marking the start of the new year, Prime Minister Noda said he will soon submit a proposal to parliament that would double the country's consumption, or sales, tax by 2015.

Growing public criticism of the tax hike proposal has already prompted nine members of Mr. Noda's Democratic Party of Japan to quit in protest. The DPJ says it is necessary to help pay for rising social security costs in the rapidly aging country.

Japan faces a historic level of debt as it continues to recover from last March's earthquake and tsunami — one of the costliest natural disasters in world history.

Mr. Noda promised that authorities would work to decontaminate the area surrounding the earthquake-stricken Fukushima nuclear power plant. He also vowed that the recovery process would be more transparent to the Japanese public.

“The problem of the nuclear power plant in Fukushima is not only a concern for the residents of Fukushima but to all nations and people around the world. It is fundamental that we provide clear an correct information to the public.”

Last month, the government announced that the plant's nuclear reactors had achieved the stable condition of “cold shutdown” and were no longer leaking substantial amounts of radiation. But it could be years before residents can return to the area.

Prime Minister Noda also said Japan will continue to coordinate with regional powers following the death of North Korean leader Kim Jong Il.

“The Korean peninsula now faces a very different situation now that Kim Jong Il has passed away. But we will continue along the lines of what we decided last year to do, that is namely: gather more information, coordinate closely with the various nations involved and prepare fully for all possibilities.”

Late Tuesday, North Korea's state news agency lashed out at Japanese lawmakers and analysts who predicted that Mr. Kim's death could mean an end to the Kim dynasty. It insisted that the Pyongyang government was the “strongest in the world,” and said Tokyo's government was the “laughingstock of the world” because of its frequent changes of prime ministers.