"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 their one-hour meeting Koizumi told Rowhani he understood that "Iran is trying to respond sincerely to the IAEA resolution and I appreciate the efforts" of Rowhani, stressing that such efforts "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."

In a working dinner with Rowhani on Tuesday, Japanese Foreign Minister Yoriko Kawaguchi called on Iran to promptly ratify the additional protocol it signed in December with the IAEA allowing inspectors to make extensive checks of its nuclear facilities in order to "rebuild the confidence of the international community", according to a Japanese official.

Rowhani said in response it would take "some more time" for the ratification and that Iranian people were concerned about "some negative views" on Tehran's nuclear programme for peaceful use, the official said.

Kawaguchi also expressed concern to Rowhani about North Korea's missile development and exports, the official said.

Rowhani told Kawaguchi Iran no longer had cooperative military relations with North Korea although the two countries had such exchanges during the Iran-Iraq war in the 1980s, the official said.

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