Talks over Iran's nuclear program might be extended if disagreement over remaining issues cannot be resolved by a November deadline, according to Reuters.

"Iran and the P5+1 (major world powers) are very serious on resolving the remaining disputes by November ... but everything including an extension is possible if we cannot reach an agreement," Abbas Araqchi was quoted as saying by the semi-official Fars news agency.

Iran rejects allegations from Western powers and their allies that it is seeking a nuclear weapons capability, but has refused to halt uranium enrichment, and been hit with U.S., European Union and UN Security Council sanctions as a result.

Top diplomats of the United States, Iran and the European Union will meet in Vienna next week to work on a comprehensive deal ahead of a Nov 24 deadline, aimed at curbing Tehran's sensitive nuclear activities in exchange for gradually lifting sanctions against Iran.

"Iran and Western powers are very determined and serious to reach a result. Issues like enrichment and lifting of sanctions will be discussed in Vienna," Araqchi said. "We are still optimistic about meeting the deadline."

Iranian and Western diplomats say significant differences remain over the future scope of Iran's uranium enrichment activity. Enrichment is a process of purifying uranium for use as fuel for power plants or, if enriched to a very high purity, for bombs.

"If we cannot reach adequate results this time (in Vienna) we will surely miss the (November) deadline," Araqchi said. "Therefore, The West (P5+1) should use this opportunity and find proper solutions."

Last year in Geneva, Iran and the six powers reached an interim agreement under which Tehran won some easing of sanctions in return for halting its most sensitive nuclear work. But they failed to meet a July 20 target for a comprehensive agreement and they sat a new deadline of Nov 24.