UNITED NATIONS, Aug. 6 (Xinhua) -- Iran's response to an incentive package offered by the United States and five other nations is "disappointing," said Alejandro Wolff, the U.S. deputy ambassador to the United Nations, on Wednesday.

    "This is a nonresponsive, disappointing response," said Wolff, speaking to reporters after a meeting of the Security Council.

    Iran has presented a letter to European Union foreign policy chief Javier Solana as a reply to the incentive package aimed at encouraging it to suspend uranium enrichment. The package was proposed by the United States, Russia, Britain, France, China, and Germany.

    Solana presented to Iran the offer of economic and trade incentives in mid-June, while Iran has put forward its own proposal that is aimed to help resolve regional and international problems, including Iran's nuclear issue.

    "The letter that the Iranians presented to Mr. Solana yesterday is disappointing," Wolff said. "We don't think it is responsive and we have to take that into account as we consult with our partners on next steps."

    Wolff accused Iran of disregarding several Security Council resolutions demanding that it cease enrichment activities.

    "Expecting the Security Council will not take that into account and remain static is unrealistic," he added.

    Meanwhile, Russia's UN Ambassador Vitaly Churkin said that Moscow did not set a deadline for Iran to respond to the offer.

    "We haven't set any deadlines ourselves for their response and there is ongoing dialogue," Churkin said, adding that the six countries will discuss the Iranian nuclear issue at a ministerial meeting in September.

    When asked if the six nations had agreed on talks to impose further sanctions on Iran, Churkin said that no definite agreement had been made.

    "To the best of my knowledge, there has been no firm agreements, or understandings, or any kind of concerted work in this regard," he said.

    "The negotiating track is open and it is being pursued and there are contacts between the parties," Churkin said.

    Churkin said that Moscow believes that some progress has been made in Iran's contacts with the International Atomic Energy Agency (IAEA) and that "better ground has been prepared for continued negotiations."

    "So let's try to focus on what kind of opportunities those negotiations can bring about," he said, suggesting that the upcoming general debate of the UN General Assembly next month may provide an opportunity for the concerned parties to discus the issue further.

    The Security Council has so far imposed three sets of sanctions against Iran for its failure to comply with demands that it halt uranium enrichment, which the United States and its Western allies said is a cover for developing nuclear arms. Iran has rejected the accusation, repeatedly stressing the peaceful purpose of its nuclear activities.