Staff writer Japan and Iran will hold high-level talks on disarmament and nonproliferation of weapons of mass destruction in Tokyo for the first time, probably during the first half of April, Foreign Ministry sources said Tuesday. The sources said the talks will be held between Norio Hattori, the Foreign Ministry's director general in charge of arms control and disarmament, and his Iranian counterpart before a four-week international conference starts in New York in late April to review the 1970 Nuclear Nonproliferation Treaty (NPT). The NPT, which restricts possession of nuclear weapons to five countries -- the U.S., Russia, China, Britain and France -- was indefinitely extended at its previous review meeting five years ago. The main purpose of the Japan-Iran talks will probably be to persuade Iran, a major military power in the Middle East, to ratify the Comprehensive (nuclear) Test Ban Treaty. But Japan apparently hopes the talks will also help thaw long-chilly relations between the Persian Gulf state and the United States, Japan's most important ally. "The U.S. still regards Iran as a rogue state, but Japan has fortunately maintained amicable ties with Iran," a senior Foreign Ministry official said, asking not to be named. The ministry sources said that prior to the Japan-Iran talks on disarmament and nuclear nonproliferation, Japan and the U.S. will also hold high-level talks on the same topic in Tokyo in early March. Since Mohammad Khatami, a liberal cleric and staunch advocate of greater political and religious freedom, was elected Iranian president in May 1997, Iran has gradually improved ties with most European countries as well as its Persian Gulf neighbors. But diplomatic relations between Iran and the U.S. have been virtually frozen since the 1979 Islamic Revolution and the subsequent hostage crisis at the U.S. Embassy in Tehran. Since its inauguration in early 1993, the U.S. administration of President Bill Clinton has pursued a policy of "dual containment" toward Iran and Iraq. Washington has accused Tehran of developing nuclear and other weapons of mass destruction as well as sponsoring terrorism and sabotaging the Middle East peace process. Tehran has vehemently denied all these charges. High-level contacts between the oil-deficient Japan and the oil-rich Iran have grown stronger since President Khatami took office. The Iranian leader is expected to make his first official visit to Tokyo sometime later this year. But under considerable political pressure from the U.S., Japan has failed to normalize official economic ties with Iran through an extension of fresh yen loans. Japan has tenaciously asked Iran to take concrete and tangible measures to dispel international concerns about terrorism and weapons development as a means of further developing bilateral ties. The CTBT, adopted at the United Nations General Assembly in the fall of 1996, stipulates that all 44 declared and potential nuclear powers must ratify the treaty before it can take effect. Of the 44 countries, only 26 have so far signed and ratified the treaty. Among the remaining 18 countries still to ratify the pact are the U.S., China and Russia. India, Pakistan and North Korea have not even signed it. Of the five declared nuclear powers, Britain and France have already ratified the CTBT. India and Pakistan are now effective nuclear powers following their nuclear tests in May 1998. Iran has signed the CTBT but has not yet ratified it. The U.S. Senate's rejection of the CTBT last October raised concern in the international community that China, Russia and other countries might be disinclined to ratify the agreement and that the trend of nuclear nonproliferation might be reversed. Japan, the only nation to have been the target of atomic bombs, has stepped up diplomatic efforts in recent months to have countries ratify the CTBT before the NPT conference.