(CNN) -- Seven months after the nuclear crisis began at Japan's Fukushima Daiichi plant, the U.S. government again warned its citizens Friday to avoid areas near the stricken reactors.
The U.S. State Department put out the travel alert -- which updates one issued about three months ago -- based on "additional data ... from Japanese authorities, allowing for a fuller assessment by U.S. government scientists."
The alert recommends that U.S. citizens stay away from any place within 20 kilometers (12 miles) from the plant. They are also being told to stay away from territory northwest of the power facility in what Japan has described as the "Deliberate Evacuation Area" and includes Iitate-mura, the Yamagiya district of Kawamata-machi, Katsurao-mura, Namie-machi and parts of Minamisoma.
Moreover, it advised all to abide by Japanese government recommendations on other spots to evacuate and urged U.S. citizens now within any evacuation zone to get out immediately.
The State Department alert offered different advice for those farther out from the plant, which it defined as between 20 and 80 kilometers. For "temporary visitors" making a trip a year, the U.S. government said that "health and safety risks ... are low and exposure does not pose significant risks."
Those who live in this zone for more than a year are being urged "out of an abundance of caution" to follow guidance from local authorities. Pregnant woman, children and elderly people should not stay within 30 kilometers (18 miles) of the plant, according to the U.S. alert.
Utility and government workers scrambled for weeks to contain the crisis at the plant, situated on Honshu island's eastern shore about 150 miles north of Tokyo, after it was impacted by a 9.0 earthquake and subsequent tsunami. Three of the facility's operating reactors melted down and spewed vast quantities of radioactive particles into the surrounding air and water, resulting in the worst nuclear accident since the 1986 Chernobyl disaster.
Some criticized the recovery effort as poorly managed at times and failing to adequately utilize outside, include international, resources. It also prompted widespread evacuations, though no one is believed to have been killed by resulting radiation -- in contrast to the more than 15,000 people killed by the quake and tsunami.
The president of Tokyo Electric Power Company, which operates the plant, told CNN last month that the recovery effort is running ahead of schedule.
Toshio Nishizawa said that a "cold shutdown" is "possible" ahead of a January deadline. That would mean decreasing temperatures in the affected reactors to under 100 degree Celsius (212 degrees Fahrenheit).
"It is the most important thing ... to show the people that Fukushima's situation is stabilized and the issue has come to the end," he said. "This is our responsibility."