The operator of Japan's tsunami-hit nuclear plant aims to reduce radiation leaks within three months and to achieve a "cold shutdown" within six to nine months.
Japan's embattled Tokyo Electric Power Co (TEPCO) offered the timeline more than five weeks after a giant quake and tsunami knocked out cooling systems at its six-reactor Fukushima nuclear power station.
The firm said the first step would be cooling the reactors and spent fuel to a stable level within three months. The second step will involve bringing the reactors to cold shutdown in six to nine months.
That would make the plant safe and stable and end the immediate crisis, now rated on a par with the world's worst nuclear accident - the 1986 Chernobyl disaster.
TEPCO, founded 60 years ago, added it later plans to cover the reactor buildings.
The latest data shows much more radiation leaked from the Daiichi plant in the early days of the crisis than first thought, prompting officials to rate it on a par with Chernobyl, although experts were quick to point out Japan's crisis was vastly different from Chernobyl in terms of radiation contamination.
TEPCO chairman Tsunehisa Katsumata said he was considering resigning over the accident, but he could not say when.
"This is the biggest crisis since the founding of our company," Mr Katsumata told a news conference at which the timetable was unveiled.
"Getting the nuclear plant under control, and the financial problems associated with that... How we can overcome these problems is a difficult matter.
"There are various risks ahead," he added. "But we aim to complete step one in about three months and step two in another three to six months."
Meanwhile, US secretary of state Hillary Clinton says Japan and the United States have agreed to create a "public-private partnership for reconstruction".
While details were vague, the heads of the countries' main business federations - the US Chamber of Commerce and Nippon Keidanren - said they would meet on ways that foreign companies could take part in the massive rebuilding.
"Economically, diplomatically and in so many other ways, Japan is indispensable to global problem-solving," Ms Clinton told a news conference after talks with Japanese foreign minister Takeaki Matsumoto.
"And the US-Japan alliance is as indispensable as ever to global security and progress."
After the disaster, US forces launched a round-the-clock relief effort bringing supplies to the battered coast - dubbed Operation Tomodachi, which means "friend" in Japanese.
US helicopters have flown aid missions from an aircraft carrier, marines have helped clear the tsunami-ravaged Sendai airport which reopened last week, and thousands joined a search of the coastline for bodies.
The United States stations around 47,000 troops in Japan under a post-World War II security treaty, often leading to friction with host communities for the military bases.
US officials hope the response to the crisis can help reshape attitudes in Japan, a staunch ally for decades.
Speaking after talks with Ms Clinton, Mr Matsumoto said America's help in the aftermath of the disaster had enabled Japanese people to "feel secure with the Japan-US alliance, including the US military in Japan".
Japan's March 11 earthquake and tsunami has killed up to 28,000 people, crippled a nuclear power plant and seriously rattled the world's third-largest economy.
Damages have been estimated at $300 billion, making it the world's costliest natural disaster.