The European Union has extended a freeze on sanctions targeting Iran by one week, EU officials said Tuesday, as tense talks on agreeing a nuclear deal continue in Vienna.

"To allow more time for the ongoing negotiations to reach a long term solution to the Iranian nuclear issue, the Council has prolonged until 7 July 2015 the suspension of EU restrictive measures," a European Council statement said.

Iran and U.S. have not had diplomatic ties for more than three decades, yet over the past 20 months they have likely sat down together more often than any other nations on Earth.

The sustained pace and intensity of the nuclear negotiations between Iran -- an Islamic clerical theocracy -- and the United States which prides itself on its constitutional freedoms, is all the more astonishing given the old enmities under the surface.

Iran's president has been pursuing a nuclear agreement for two years but even if a deal is reached Hassan Rouhani and his government will soon face mounting political pressure at home.

Having sought to end the nuclear crisis -- and with it the international sanctions that have paralyzed Iran's economy -- Rouhani's fate is often seen as inextricably linked to the negotiations.

French Foreign Minister Laurent Fabius said Monday he plans to return to Vienna this week as world powers work to finalize a landmark deal on Iran's nuclear program.

"I will be back in Vienna this week," Fabius told reporters in New York where he was to attend a U.N. event on climate change.

Sarah Hekmati's young son had it all figured out. He'd burst into Iran's notorious Evian jail with Superman and Batman and free his uncle to bring him home to the United States.

At this point the family of Amir Hekmati feels it may need superhuman intervention to free the former U.S. Marine, who has been imprisoned in Iran since 2011.

A cultural row in Iran over concerts being canceled was reignited Sunday when the country's judiciary chief appeared to criticize President Hassan Rouhani's liberal remarks on the subject.

Music and other public performances are a sensitive matter in the Islamic republic given concerns among religious conservatives about creeping "Westernization". But there is a desire from other groups, particularly younger citizens, for greater artistic freedom.

Iran's foreign minister flew home late Sunday for consultations after an intense day of talks with major powers, as a looming deadline for a historic nuclear deal looked set to slip by a few days.

A senior U.S. official at the talks in Vienna would not say there was no chance of nailing down the accord by Tuesday, but admitted "it's fair to say the parties are planning to stay past (June 30th) to keep negotiating." 

Iran has condemned the jihadist attacks in Tunisia, Kuwait and France, saying they were "contrary to the teachings of Islam," in statements released Saturday by the foreign ministry.

The killings were not apparently coordinated, but the Islamic State group claimed the atrocities in Tunisia and Kuwait, just days before the first anniversary of it declaring a "caliphate" in Iraq and Syria.

Efforts to finalize a historic nuclear deal with Iran remain stuck on several issues, diplomats from both sides said Friday as U.S. Secretary of State John Kerry headed to Vienna for crunch weekend talks.

"Some major problems exist which are still blocking the work... but in other areas we have made good progress," Iranian Deputy Foreign Minister Abbas Araghchi told state television from the Austrian capital, four days before a deadline for a deal.

Days before the deadline for an Iranian nuclear deal, Israeli Prime Minister Benjamin Netanyahu told young pilots Thursday that they would be at the forefront of safeguarding Israel.

"Foremost among the threats endangering our security is the Iranian effort to arm itself with a nuclear weapon," a statement from Netanyahu's office quoted him as telling newly-graduated pilots receiving their wings.