Iran said it was willing to resume unconditional talks with the European Union over its nuclear program, which Washington says is a cover to make atomic bombs.
Talks between the European Union and Iran collapsed in August after Tehran restarted uranium conversion, suspended under a November 2004 deal with France, Britain and Germany.
The European Union has said it was up to Iran to suspend conversion again and cooperate fully with the IAEA for talks to resume.
Washington and the EU are trying to persuade the governing board of the International Atomic Energy Agency (IAEA) to send Iran to the U.N. Security Council in November for violating international nuclear obligations.
They say Iran is pursuing nuclear weapons, but Tehran insists its nuclear program is dedicated solely to generating electricity.
Ali Larijani, secretary-general of the Supreme National Security Council, said on Monday Tehran would review its membership of the Non-Proliferation Treaty if its case was reported to the council.
Hardline parliamentarian Mehdi Kouchakzadeh said on Tuesday talks with the Europeans were a "waste of time".
"Iranian officials should not wait for the EU's shallow promises any more," he told.
"We should also start uranium enrichment in Natanz and think about ending snap (U.N.) inspections."
Iran has so far refrained from resuming work at its Natanz uranium enrichment facility, Reuters reports.