Geneva, Switzerland (CNN) -- Iranian officials sat down Monday with the United States and other countries trying to put the brakes on Tehran's nuclear program, a day after Iran announced it is self-sufficient in the nuclear fuel cycle. There was "an exchange of views and concerns," between the Iranians and envoys from the five permanent members of the U.N. Security Council, plus Germany, a diplomatic source familiar with the talks told CNN. The Iranian nuclear program was the main issue on the table, the source said. Iran has previously said it did not want the talks to focus on that.
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NEW: Sources say the talks are over for the day and will resume Tuesday
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U.S., British, Chinese, Russian, French, German and Iranian officials meet
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The discussions are the first on Iran's nuclear program since over a year ago
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Iran expresses concern about attacks on its nuclear scientists
Iran also raised some of its concerns, the source said, including attacks on two @placeholder scientists in Tehran last week that left one dead and one injured.