IIran's Supreme Leader Ayatollah Ali Khamenei vowed he will not allow international inspection of Iran's military sites or access to Iranian scientists under any nuclear agreement with world powers. (Office of the Iranian Supreme Leader/AP)

Negotiations aimed at reaching a deal over Iran’s nuclear program could extend beyond a self-imposed June 30 deadline and are not bound by a “specific time,” a senior Iranian envoy said Wednesday.

The comments appear to strengthen predictions that the talks between Iran and six world powers may not settle on a final agreement in the next month, but negotiators could press ahead if there is progress toward an accord.

Any overtime efforts, however, are likely to amplify criticism from those questioning the talks, including some U.S. lawmakers and Iranian hard-liners.

“The deadline might be extended and the talks might continue after the June 30” deadline, senior Iranian nuclear negotiator Abbas Araghchi was quoted as saying by Iranian state TV after arriving in Vienna for meetings with the U.N. nuclear watchdog, the International Atomic Energy Agency.

“We are not bound to a specific time,” he added. “We want a good deal that covers our demands.”

Secretary of State John F. Kerry has expressed hope that an accord can be reached by the deadline but noted that Iran must still answer past questions from U.N. nuclear inspectors that include details about military sites.

On Tuesday, France’s ambassador to the United States, Gérard Araud, predicted that achieving a firm accord by June 30 is “very unlikely” because a host of technical issues remain unresolved.

In addition to France and the United States, negotiators from China, Russia, Germany and Britain have been working on hammering out the deal, which seeks to rein in Iran’s nuclear program in exchange for easing international economic sanctions.

The West and its allies fear Iran’s ability to make nuclear fuel could eventually lead to the production of weapons-grade material. Iran insists it only seeks to power reactors for energy and medical applications.

The rifts over the nuclear talks were highlighted this week in a video circulating on Internet sites that purports to show a heated exchange in Iran’s parliament between Foreign Minister Mohammad Javad Zarif and hard-line lawmaker Mahdi Kouchakzadeh.

Kouchakzadeh calls Zarif a “traitor.” Zarif responds that the lawmaker has no right to claim to speak on behalf of Iran’s supreme leader, Ayatollah Ali Khamenei.

Khamenei, who has the final say in all state matters, has permitted the nuclear talks. But he raised potential snags last week, saying Iran could not allow U.N. inspectors to visit military sites or interview high-ranking defense officials.

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