Rafsanjani was speaking a day after Iran signed a protocol to the nuclear Non-Proliferation Treaty (NPT), which allows for snap inspections of Tehran's nuclear sites by the International Atomic Energy Agency (IAEA).
"The ball is now in the (Westerners') court," he said. "We have a long time until the definitive adoption of the additional protocol" by the Iranian parliament. "If the other countries also keep to their commitments, the process that is underway will succeed."
Rafsanjani was insisting that, in exchange for signing the protocol and for steps it has taken in recent months to shed light on its nuclear program, Western countries help it "by furnishing the technology necessary" for developing civilian atomic energy.
"But if they want to trick us, to profit from the situation or to create a climate of menace and fear, they will get nothing," he warned in a sermon preached at Friday prayers and broadcast by state radio.
"I hope that the leaders of the world will have the intelligence to understand that it is the interests of the region and of the world for them to fulfill their commitments."
The protocol obliges signatory countries to provide the IAEA with much more precise information about their nuclear activities than is required under the
And it authorizes the IAEA to carry out more intrusive inspections of nuclear facilities.
Under the agreement, states commit to giving IAEA inspectors information about, and short-notice access to, all parts of their nuclear fuel cycle.
They must also offer access to any location where nuclear material is or may be present, and the IAEA may give as little as two hours' notice before it visits a site.
The United States and other Western countries suspect that Iran has been using its civil atomic energy program as a cover to develop nuclear weapons, something Tehran roundly denies.