Larijani submitted Iran's formal response to the envoys from China, Russia, France, Germany, Britain and Switzerland.

Switzerland is representing the United States since Washington has no diplomatic relations with Iran.

No details concerning the response was available now, but officials close to the meeting disclosed that the response had offered a "new formula" to resolve the disputed nuclear issue.

"Iran has given an all-sided response to the package, but also raised some questions," one of the officials said.

Iran's state television on Tuesday termed the response as Iran's commitment to dialogue and promises, saying "Iran's response reveals that Iran is committed to dialogue and its promises ... It is in contrast with America's policy of unilateralism."

Iran has promised to give an official response by Tuesday to the package of proposals, which was authored by the United States, Russia, China, France, Britain and Germany in June.

The package, designed to defuse the current tensions over Iran's nuclear program, includes both incentives aimed at persuading Iran to suspend uranium enrichment and possible sanctions if Iran does not comply.

On Monday, Supreme Leader Ayatollah Ali Khamenei said that Iran would continue its nuclear energy work.

Deputy Director of Iran's Atomic Energy Organization Mohammad Sa'eedi also said that suspension of uranium enrichment was "practically impossible" even though the UN Security Council has made such a demand.

The Security Council adopted a resolution last month urging Tehran to suspend by Aug. 31 all enrichment-related and reprocessing activities, including research and development, or face prospect of sanctions.

The United States has accused Iran of secretly developing nuclear weapons under a civilian front, a charge categorically denied by Tehran which says that its nuclear program is for peaceful purposes.