The head of the U.N. nuclear agency says Iran's refusal to suspend uranium enrichment is "regrettable," but said its willingness to cooperate with U.N. investigators is a step in the right direction. From VOA's New York Bureau, Mona Ghuneim reports on the agency's efforts to work on a diplomatic solution with Iran.

Head of the International Atomic Energy Agency, Mohamed ElBaradei, says Iran recently agreed to work with U.N. investigators, but insists complete cooperation and transparency are still needed.

Speaking to the General Assembly Monday, ElBaradei said the agency has been unable to verify certain important aspects of Iran's nuclear program. He expressed regret that Iran was continuing to build a heavy water reactor and said Iran must prove to the international community that it is serious about using nuclear power for peaceful purposes.

"If the agency were able to provide credible assurances about the peaceful nature of Iran's past and current nuclear program, this would go a long way toward building confidence and could help create the conditions for a comprehensive and durable solution," he said.

The U.S. representative to the United Nations, Zalmay Khalilzad, says resolving the Iranian nuclear issue is essential and western nations are drafting a new UN resolution to increase pressure on Iran. Washington imposed new sanctions on Iran last week and there has been speculation that harsher measures may be taken.

Khalilzad says an agreement with Iran to suspend uranium enrichment must be obtained immediately.

"Given the record of this regime, given the rhetoric of this regime, the policies of this regime, the connections of this regime, it cannot be acceptable for it to develop the capability to produce nuclear weapons," he said.

ElBaradei said on Sunday there was no evidence that Iran was trying to make nuclear bombs and that the country was still years away from having that capability. But the United States and other western countries, such as France, suspect Iran has a weapons program. Iran continues to deny the charge, saying its nuclear program is for energy.

Iranian Ambassador to the U.N. Mohammad Khazaee says Iran has a right to develop nuclear technology for peaceful purposes.

"All reports issued by the IAEA since November 2003 have been indicative of the peaceful nature of the Iranian nuclear program and the agency has repeatedly reaffirmed that it, quote, 'has not seen indications of diversion of nuclear material to nuclear weapons or other nuclear explosive devices,' unquote," he said.

Iran's deal with the U.N. agency has been criticized for allowing Iran to "play for time," but ElBaradei says Tehran's agreement in August to clear up its nuclear record by the end of the year is an important step in the right direction.