"Japan-Iran relations have been strengthening as seen in the agreement to develop the Azadegan oilfield, and I very much hope this will go further," Koizumi was quoted as telling Iran's top nuclear policy-maker Hassan Rowhani.

Japan announced on February 19 it had signed an agreement with Iran to develop the massive Azadegan oilfield in order to assure stable oil supplies. The deal unnerved Washington which expressed its "deep concern" due to suspected nuclear developments in Iran.

During the one-hour meeting with Rowhani, Koizumi also noted Iran's "efforts to solve the nuclear issue and a sincere response to the IAEA resolution are very important for developing ties between Japan and Iran," the Japanese official said.

The International Atomic Energy Agency (IAEA) has called on Tehran to disclose details of its nuclear programmes by June.

Rowhani, secretary general of Iran's Supreme National Security Council, told reporters Tuesday Tehran was to accept an inspection by the UN nuclear watchdog unconditionally from March 27.

Iran had put off inspections scheduled for last week in order to protest the drafting of a tough resolution by the IAEA against Tehran for hiding sensitive parts of a programme the United States claims is devoted to secretly developing nuclear arms.

Rowhani assured Koizumi that Tehran "will continue cooperating with the IAEA so that the international community will have no concern over Iran's peaceful use of atomic energy," the official said.

"We want to prevent the nuclear issue from being used for political purposes," he was quoted as saying through a translator.

Rowhani, widely considered Iran's leading presidential candidate, also said he wanted to develop ties with Japan "over the long term and comprehensively."

WAR.WIRE