Rafsanjani, speaking Friday at a prayer congregation in Tehran, said Israel and the West need to "accept realities" and acknowledge a country's right to pursue peaceful nuclear technology, the Khaleej Times reported.
"We have agreed to talk (with the world powers) on the issue for finding a settlement (in the nuclear dispute) and are indeed hopeful to do so," Rafsanjani said. "But again they come up with ultimatums, timetables and even threats which are unacceptable for Iran."
The five members United Nations Security Council plus Germany have given Iran a two-week deadline to either freeze its uranium enrichment activities and in return gain Western economic and political incentives, or face further financial sanctions.
Iran denies its nuclear program is meant to produce atomic weapons.