The European Union's energy chief called for a reassessment of the 27-nation bloc's energy policy, and questioned what role nuclear power should have in the future.
"We have to ask ourselves: Can we in Europe, within time, secure our energy needs without nuclear power plants?" EU Energy Commissioner Guenther Oettinger told German ARD television.
Energy ministers, nuclear regulators and industry officials meeting in Brussels found "general agreement" on the need for tough tests to check whether the EU's 143 nuclear reactors could withstand earthquakes and other emergencies, Oettinger said.
The stress tests will be devised using the "strictest" nuclear standards in the bloc and be applied in second half of the year, he said, adding that plants that fail the tests would have to shut down.
"The authority of the test must be so high, that those responsible will have to live by the consequences," Oettinger said.
He invited non-EU nations including Russia and Switzerland to join the initiative.
Earlier Tuesday, German Chancellor Angela Merkel said that seven reactors that went into operation before 1980 would be offline for three months while Europe's biggest economy reconsiders its plans to extend the life of its atomic power plants.
One of them, the Neckarwestheim I reactor, would remain shut down for good. Residents said living in the shadow of the 35-year-old nuclear plant is making them increasingly nervous in the wake of the events in Japan.
"It must be switched off," 32-year-old Anja Pfau told AP Television News as she pushed her 5-month-old boy along the street in a pram. "There are enough alternative energies like water power and solar energy."
A previous government decided a decade ago to shut all 17 German nuclear reactors 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.
Oettinger said no other EU country had followed Germany's move to shut down old reactors. Switzerland, which is not in the EU, on Monday suspended plans to replace and build new nuclear plants pending a review of the tsunami-stricken reactors in Japan.
Energy policies in the EU are still driven independently by member nations and vary hugely. For example, France gets about 84 percent of its energy from nuclear power, while Poland relies mostly on coal and solid fuels.
Though earthquakes are rare in Germany and tend to be weak, Merkel said effects of the Japan temblor made clear that the measures taken there to protect nuclear plants were insufficient - justifying a review of precautions elsewhere.
"This has shown that the design of the nuclear plants were not sufficient against the forces of nature," she said.
Merkel said she has already spoken with French President Nicolas Sarkozy, agreeing to bring up nuclear safety as a topic at the G-20 summit in France at the end of the month. Oettinger expected an EU summit next week would also focus on that issue.
Separately from the EU stress test initiative, France ordered safety checks of its 58 nuclear reactors to determine their capacity to resist earthquakes or floods. Prime Minister Francois Fillon called it "absurd" to say that explosions at a Japanese nuclear plant will "condemn" nuclear energy.
But there was no avoiding a psychological impact from the events in Japan, even as the problems at the crippled Fukushima Dai-ichi nuclear plant got worse on Tuesday.
"This might have dark and difficult consequences. But we still really don't know what the results will be. Thereafter we'll be able to judge what is of relevance for our security work," Swedish Environment minister Andreas Carlgren said ahead of Tuesday's meeting in Brussels.
The more than 100 Cabinet ministers, regulators and nuclear industry officials looked at how to confront emergencies and what can be done better, with special emphasis on what kind of emergency power supply and backup systems are in place.
Only half the EU nations produce nuclear energy but any serious accident would soon involve all.
In Ankara, Turkish Prime Minister Recep Tayyip Erdogan, whose country is not an EU member, said he had no plans to suspend a deal with Russia's Rosatom agency for the construction of Turkey's first nuclear power plant.
Dismissing questions on possible dangers, Erdogan said all investments have high risks. "In that case, let's not bring gas canisters to our homes, let's not install natural gas, let's not stream crude oil through our country," he said.
Russia signed another deal with Belarus on Tuesday to build a nuclear power station there. Russian Prime Minister Vladimir Putin said the facility would be safer than that threatend by meltdown in Japan.
Moulson reported from Berlin. David Rising and Melissa Eddy in Berlin, Susan Fraser in Ankara and Liudas Dapkus in Vilnius, Lithuania, also contributed to this report.