A recent U.S. report that concluded with "high confidence" that Iran halted its nuclear arms program in 2003 offers a key opportunity to expand Japan-Iran ties, Iranian Ambassador to Japan Mohsen Talaei said.

"The affirmation of the use of peaceful nuclear energy in Iran was not unexpected," Talaei said in a recent interview in Tokyo. "I hope the NIE (National Intelligence Estimate) report will create more realism in U.S. policies toward Iran. Naturally, our expectations from Japan, which has amicable relations with the U.S. and Iran, are also high."

Iran is hoping that Japan will resume investments in developing its oil fields. Japan withdrew from an agreement to develop the Azadegan oil field in western Iran, near the Iraqi border, in October 2006 under U.S. pressure.