The five permanent members of the U.N. Security Council, Germany and Iran concluded two days worth of nuclear negotiations last weekend in Kazakhstan. U.N. nuclear inspectors said there may be a military dimension to certain parts of Iran's nuclear program, an allegation the Iranian government denies.
Hossein Naqavi Hosseni, a special envoy for Iran's foreign policy commission, told the semiofficial Fars News Agency that enrichment was off the table.
"We don't accept the literature of suspension or halt from any one and negotiations about it are our red line but we are ready to negotiate about the purity level of (uranium) enrichment," he said Monday.
Iran says it has the right to pursue peaceful nuclear research under the terms of the nuclear Non-Proliferation Treaty.
The European Union's top foreign policy official, Catherine Ashton, said last weekend that both sides remained "far apart on the substance" of multilateral proposals.
"We have therefore agreed that all sides will go back to capitals to evaluate where we stand in the process," she said in a statement.
Western powers had offered Iran certain concessions on economic sanctions in exchange for assurances about its nuclear research activity.