BERLIN -- Germany will take seven of its 17 nuclear reactors offline for three months while the country reconsiders plans to extend the life of its atomic power plants in the wake of events in Japan, Chancellor Angela Merkel said Tuesday.

Germany will temporarily shut down all reactors that went into operation before the end of 1980, Merkel said after meeting the governors of states that have nuclear plants. She noted that not all are currently on the grid, because of maintenance work.

Ahead of three state elections over the next two weeks, Merkel has performed a partial policy about-turn amid fears sparked by the crisis under way at Japan's tsunami-stricken nuclear power plant.

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A previous government decided a decade ago to shut all 17 German nuclear plants by 2021, but Merkel's administration last year moved to extend their lives by an average 12 years. That decision was suspended for three months on Monday.

"Safety is the priority," Merkel said. "Those are the criteria by which we acted today."

Environment Minister Norbert Roettgen characterized the planned shutdown as a "precaution" pending a safety review of all nuclear plants but wouldn't say whether it might lead to the oldest reactors being shuttered permanently.

"We can't have the result already on the first day of the process," he said.

Nuclear energy has been unpopular in Germany since an explosion at a nuclear reactor at Chernobyl, Ukraine, in 1986, sent a cloud of radiation over much of Europe.

Extending nuclear plants' lives was a divisive move even though Germany, unlike other European countries, has no plans to build new facilities.

Merkel describes nuclear energy as a "bridging technology" that the country needs to keep using for now to keep power affordable pending development of more renewable energy sources.

In Brussels, European Union energy officials and nuclear regulators planned an emergency meeting Tuesday to assess the security of nuclear plants in the 27-nation bloc.

The meeting was not meant to debate the overall question of whether the nuclear industry should be scaled down, but was expected to limit itself to urgent and practical safety checks.