The Iranian regime has not been flexible enough in talks with the West aimed at halting the regime's project to build a nuclear bomb, officials from Britain and France said this week.
The criticism of Iran's stance at the end of another round of negotiations between the regime and officials from the United States, Britain, France, Germany, Russia and China.
Senior French diplomat Philippe Bertoux told the UN Security Council: "In spite of insufficient flexibility demonstrated at this stage by Iranian negotiators, we'd like to believe that Iran does seek a long-term agreement.
"We would expect that Iran takes strategic choices and courageous decisions in upcoming rounds of negotiations."
Senior British diplomat Michael Tatham also urging Iran to be more flexible in the next round of negotiations.
Western officials say Iran has not compromised on major sticking points in the talks, including the size and scope of its future uranium enrichment program and the speed of ending sanctions.
Deputy US Ambassador David Pressman said: "While we continue to believe that the best way to achieve our goals is thorough diplomacy, we are not going to sit at the negotiating table forever."
He said the UN Security Council's sanctions committee should continue monitoring the implementation of UN sanctions, and referred to a recent report by the Iran Panel of Experts which said Tehran was continuing to skirt the sanctions.
Mr Pressman added: "We know that Iran is still trying to procure sensitive technology. We know Iran is still smuggling arms in violation of the UN arms embargo on it."