This will be part of an exchange visit with Mr Cook's Iranian opposite number Kamal Kharrazi, who will make a trip to London before the end of this year.
The visits were settled at an hour-long meeting between Mr Cook and Mr Kharrazi yesterday on the margins of the United Nations General Assembly in New York . The move builds on the watershed agreement made here 12 months ago when the Iranian government disassociated itself from the fatwa issued against Salman Rushdie by the country's religious authorities.
The improvement in ties includes the recent exchange of ambassadors, stepped-up trade and closer collaboration on matters of mutual concern, not least the trade in heroin.
But vast differences in cultural and political attitudes still divide London and Tehran. These are further complicated by the power struggle between moderates and religious conservatives in Iran.
"A thaw can take a long time," Mr Cook declared. "The exchange of visits is a big step forward, but there's still a long road ahead. Iran is going through a period of transition ... those of us who want to see Iran become part of the international community hope that the forces of reform will continue to grow in strength."
The acid test will be the Iranian parliamentary elections next February. But even in New York the conflict surfaced obliquely, in Mr Kharrazi's response to Mr Cook's questions about the students allegedly sentenced to death for fomenting July's riots in Tehran. The Foreign Minister denied to Mr Cook that any sentences had been handed down, British officials said.
Mr Cook was pessimistic that Britain's attempt to forge a Security Council compromise on an easing of sanctions and a resumption of UN weapons inspections would yield fruit this week. Iraq seemed to close the door in advance by insisting on an unconditional end to sanctions, something that even its strongest supporters, France and Russia, are ready to countenance.
In his speech to the Assembly yesterday, President Clinton too was in an uncompromising mood on Iraq. He expressed sympathy for the suffering of civilians but warned: "We can't allow Iran to flout 40 successive Security Council resolutions and rebuild its arsenal of weapons." His remarks are asign that without the resumption of weapons inspections, Washington will not consent to any removal of sanctions.Reuse content