U.S. Secretary of State Hillary Rodham Clinton on Sunday promised solidarity and support for longtime ally Japan as it recovers from a devastating earthquake and tsunami and copes with a nuclear crisis.

"We pledge our steadfast support for you and your future recovery. We are very confident that Japan will demonstrate the resilience that we have seen during this crisis in the months ahead," she told reporters after meeting with Foreign Minister Takeaki Matsumoto.

Japan is determined to do a better job in preventing nuclear accidents such as the one that unfolded at the Fukushima Dai-ichi nuclear power plant after a tsunami triggered by a magnitude-9.0 earthquake on March 11 wrecked its cooling and power systems, Matsumoto said.

"Nuclear safety has to be improved," he said.

Tokyo Electric Power Co., the crisis-plagued operator of the nuclear plant, said it has drawn up a timeline for resolving the accident and presumably ending radiation leaks that have forced the evacuation of tens of thousands of people.

Details were due to be announced later Sunday.

Clinton said Matsumoto told her that Japan would welcome U.S. feedback on the plan.

"The constant efforts to respond to the situation at Fukishima have required intense analysis by Japanese, American and international experts, and we have been very supportive of what Japan is doing to take the appropriate steps," she said.

Clinton and Matsumoto announced the formation of a public-private partnership to encourage investment in the recovery effort. The aim is to keep American businesses interested in Japan by demonstrating its resilience in the face of daunting natural disasters.

Clinton, who called Japan's well-being a "bedrock priority," was also due to meet with Prime Minister Naoto Kan and the emperor and empress before heading back to the U.S. later in the day.

"There has been a great outpouring of concern, sympathy and admiration for the great resilience and spirit the Japanese people have shown throughout this very difficult experience," Clinton said.

Just one year after tensions over U.S. military bases in Japan forced out a prime minister, relief operations mounted by American soldiers after the earthquake and tsunami helped show a new and welcome face for troops the Japanese have hosted — sometimes grudgingly — for decades.

Roughly 20,000 U.S. troops were mobilized in "Operation Tomodachi," or "Friend," the biggest bilateral humanitarian mission the U.S. has conducted in Japan. The U.S. is also helping Japan cope with the nuclear crisis.

Matsumoto said the efforts had encouraged the Japanese and reaffirmed the friendship between the U.S. and Japan.