A senior U.S. official said Wednesday that six of the world's nuclear powers and Iran will work toward clearing a long-standing impasse over the latter’s nuclear program by a Nov. 24 deadline. However, the official added that there were significant gaps that needed to be addressed before a deal could be finalized.

The statement came before Wednesday's meeting between U.S. Secretary of State John Kerry, Iranian Foreign Minister Mohammad Javad Zarif and the European Union’s foreign policy chief Catherine Ashton in Vienna, to discuss Iran's nuclear program. A key negotiator from Iran had raised the possibility of extending the deadline to help resolve the deadlock between Iran and the six world powers, which include the U.S., Russia, China, Britain, France and Germany.

"We don’t know if we’ll be able to get to an agreement, we very well may not,” the State Department official said, according to Reuters, adding: “We’re not talking about extension or anything like that in the room. We’re talking about getting this done by the 24th (of November)."

Russian Foreign Minister Sergei Lavrov reportedly said on Tuesday that the deadline was not "sacred," raising expectations that it may be extended.

Both parties have met several times over the past few months to discuss reducing economic sanctions against Iran if it stops its efforts to enrich uranium. In July, after meetings held that month failed to provide a solution, the group extended the deadline to November. Although Iran has repeatedly said that its nuclear program is for research purposes, Western powers believe it is an excuse to develop nuclear weapons.

"There is still time to get this done. There’s enough time to get the technical work done, to get the political agreement ... if everybody can make the decisions they need to," the U.S. official said, according to Reuters, adding: "We keep chipping away ... In places gaps have narrowed, but the Iranians have some fundamental decisions to make.”