The U.S. wants Iran to end all uranium enrichment. The European nations have yet to make clear their position. The JCPOA limited Iran to enriching uranium up to 3.67% purity -- sufficient for civilian nuclear power purposes but below the 90% purity needed for use in a weapon.

Newsweek has reached out to the U.S. State Department for comment. If talks fail to get back on track, there is a higher risk of further military action against Iran's nuclear program from the United States as well as Israel.

Iran and European powers agree they need to hold another round of nuclear talks soon following discussions in Istanbul on Friday, said Iranian Deputy Foreign Minister Majid Takht-Ravanchi.