"The method of cooperation could change if the realities are ignored," Asefi told a press conference, while adding, "the question of cooperation is not at issue."
Asefi was speaking after a US-backed resolution by the International Atomic Energy Agency condemning Iran for hiding possibly weapons-related nuclear activities prompted Tehran to suspend the return of IAEA inspectors scheduled for Saturday.
"We have cooperated with the IAEA and we are still interested in this cooperation because we are clear on our objectives and intentions", he said.
Asefi said remarks Wednesday by Foreign Minister Kamal Kharazi indicating that Tehran could break ties with the IAEA had been misinterpreted.
Kharazi had said, "We are engaged in cooperation (with the IAEA), and for this to continue the cooperation has to be bilateral. If one side does not respect its obligations, the cooperation will end."
"We advise the Europeans to respect their obligations and to resist American pressure, otherwise there is no reason for cooperation to continue," Kharazi added.
Asefi said the return of the inspectors would have to be renegotiated.
"The necessary coordination will take place with the IAEA for the visit of the inspectors and the conditions and date of their arrival will be the subject of discussions", spokesman Hamid Reza Asefi told a press conference.
He branded the IAEA resolution "unfair and insulting," saying the cancellation of the inspection team's visit was Tehran's response to it.
"We will not allow anyone to speak of the Islamic republic in this manner," Asefi warned.
He dubbed "inacceptable" IAEA demands for a complete accounting of Iran's nuclear activities, stressing that Tehran had "nothing to hide."
And he said that the refusal to allow in the inspectors should not be used as a pretect to refer Iran to the UN Security Council, which could decide to implement sanctions.