The United States warned of Iran on Tuesday that it will consider possible actions against Iran if Iran does not fulfill its obligations to stop its sensitive nuclear activities.
"Iran has an obligation right now to reassure the international community that its statements about not seeking nuclear weapons are true," State Department spokesman Richard Boucher said at a news briefing.
Iran needs to turn its temporary suspension into a permanent cessation of uranium enrichment activity, Boucher said, noting "Refusal by Iran to do this, that and the other is not going to get them anywhere."
"The only way Iran is going to get anywhere with the Europeans or with the rest of the world is by accepting freely its obligations and undertaking to fulfill them.
"Unfortunately, we've not seen that kind of attitude from Iran, and we may have to consider what other action to take if Iran does not fulfill its obligations," Boucher said.
Iran's chief nuclear negotiator Hassan Rowhani warned last weekend Tehran will stop all confidence-building measures if the ongoing nuclear negotiations with the European Union (EU) fail.
"If the talks fail due to the US pressure and Iran's nuclear case is sent to the UN Security Council, we will stop all confidence-building measures and the regional security will face problems," Rowhani said at the International Conference on Nuclear Technology and Sustainable Development.
Iran and the EU are going to start a new round of talks on Tehran's nuclear program later this week.
Iran and the EU have finished three rounds of negotiations since Iran suspended its highly sensitive uranium enrichment activities last November.
Washington accuses Iran of trying to covertly develop nuclear arms. Iran rejects American allegations, and insists its nuclear activities are peaceful and geared solely toward generating electric power.