This is the first time the government is allowing short trips into the zone near the disabled Fukushima Dai-ichi nuclear plant.
Naoto Kan said Japan needs to revise its long-term energy policy after the Fukushima Dai-ichi nuclear power plant was heavily damaged by a March 11 earthquake and tsunami and began leaking radiation.
Some 80,000 people living within a 12-mile radius of the plant were evacuated from their homes, with many living in gymnasiums.
Japan will scrap a plan to obtain half of its electricity from nuclear power and will instead promote renewable energy and conservation as a result of its ongoing nuclear crisis, the prime minister said Tuesday.
Nuclear plants supplied about 30 percent of Japan's electricity, and the government had planned to raise that to 50 percent by 2030.
"We will thoroughly ensure safety for nuclear power generation and make efforts to further promote renewable energy," Kan said.
Kan also said he would take a pay cut beginning in June until the Fukushima nuclear crisis is resolved to take responsibility as part of the government that has promoted nuclear energy. He didn't specify how much of a pay cut he would take.
"I believe the government bears a major responsibility for having promoted nuclear energy as national policy. I apologize to the people for failing to prevent the nuclear accident," Kan said.
The Associated Press contributed to this story