Russia will insist on a diplomatic solution to the Iranian nuclear crisis when diplomats from six countries involved in searching for a resolution meet in Moscow this week, the Russian Foreign Ministry said Monday. "We proceed from the assumption that the Iranian nuclear problem should be solved through diplomacy," ministry spokesman Andrei Krivtsov told The Associated Press. "This opinion is invariable and it will be reaffirmed at the upcoming talks." Political directors of the foreign ministries of Russia, the United States, China, Germany, France and Britain will meet over dinner Tuesday to discuss Iran, a Western diplomat said on customary condition of anonymity. Deputy Foreign Minister Sergei Kislyak will represent Russia; Undersecretary of State Nicholas Burns, the United States; and Assistant Foreign Minister Cui Tiankai, China.