Nuclear talks between Iran and six world powers have virtually stalled and the June 30 deadline for a final deal may have to be postponed yet again, Reuters reported on Friday, citing a diplomatic source who spoke to the Russian news agency TASS.

Iran and the six major powers reached a framework nuclear deal on April 2 in Lausanne, Switzerland, and are seeking to reach a final agreement by the June 30 deadline, but still have to work out differences on several issues.

The United States has said it stands by the end-June deadline for the deal, meant to assuage Western fears that Iran is working to develop a nuclear bomb, and has made clear the talks will not be extended again.

But other officials have indicated the date might be missed as negotiations about technical details drag on.

Iran denies any ambition to develop nuclear weapons and says its program is for generating electricity and other peaceful purposes.

The latest round of discussions in Vienna on Friday had made no significant progress, the source from one of the missions said, according to TASS.

“The process has virtually stalled, there is risk that deadline will have to be postponed again,” TASS said the source added.

Among the unresolved issues are the pace of easing Western sanctions imposed over the Iranian program and the monitoring and verification measures to ensure Iran could not pursue a clandestine nuclear weapons program.

 Iran has categorically denied reports that it would allow inspectors into its sites as part of a final deal, describing them as mere rumors and as wrong interpretations of the understanding reached in early April.

Iran’s Deputy Chief of Staff last week reiterated that the Islamic Republic will not allow any inspection of its military sites, calling the demand to do so “excessive”.

(Arutz Sheva’s North American desk is keeping you updated until the start of Shabbat in New York. The time posted automatically on all Arutz Sheva articles, however, is Israeli time.)