A senior Iranian negotiator was upbeat Monday about the chances of progress in the latest round of talks about a proposed U.N. investigation of his country’s nuclear program, promising “new approaches” meant to end nearly two years of deadlock.

Deputy Foreign Minister Abbas Araghchi spoke to reporters after meeting with Yukiya Amano, the head of the U.N.’s International Atomic Energy Agency, and shortly before IAEA and Iranian officials sat down to negotiate again about the terms of the IAEA investigation.

Nearly two years of Iran-IAEA meetings have made little progress on terms of an agency investigation into suspicions that Tehran may have worked secretly on nuclear arms. Iran has no such weapons and denies working on them.

Araghchi did not give details about Iran’s position, but in remarks to reporters loaded with optimism, he spoke of a “very useful and constructive meeting” with Amano, and said he was “very hopeful” that the talks on the proposed probe will break “with a good result.”

Most recent meetings have ended the same day they started. But the two sides concluded Monday’s talks by agreeing to resume negotiations today, suggesting they had more topics in common than usual.

Beyond any new Iranian initiative, Araghchi’s visit is significant on its own. He and other senior Iranian officials have repeatedly expressed willingness to work on reducing fears about Iran’s nuclear aims since reformist Iranian President Hassan Rouhani took office in August.

Araghchi was a senior negotiator for Iran at Geneva talks earlier this month with six world powers that are seeking cuts in programs that Iran says serve only peaceful purposes but which could be re-engineered to make nuclear arms.

A new round in Geneva is scheduled for next week after both sides described the earlier talks as positive. Araghchi’s meeting with Amano in Vienna could be interpreted as a symbol of Iranian interest in resolving the impasse on the IAEA probe in parallel with the six power talks.

While the Vienna and Geneva talks are formally separate, they are linked by concerns over Iran’s nuclear aspirations, and progress in one may result in advances in the other.

The Vienna talks have been deadlocked for nearly two years, with agency experts seeking an open-ended probe and Iran insisting that it be carefully scripted with limits on what can be inspected, who can be questioned and other constraints.

But officials from both sides spoke of a “constructive” meeting after the latest round last month. That assessment, and reports of progress in Geneva, are both seen as encouraging tests of pledges by Rouhani to reduce nuclear tensions.

As part of its probe, the IAEA is trying to gain access to a sector at Parchin, a sprawling military establishment southeast of Tehran. The agency suspects the site may have been used to test conventional explosive triggers meant to set off a nuclear blast.

Amano told reporters earlier this year he was concerned about satellite images showing asphalt work, soil removal and “possible dismantling of infrastructures” at the site.

Iran says such activities are part of regular construction that has nothing to do with alleged attempts to cleanse the area of evidence.

Vienna also is the venue this week of a meeting linked to the Geneva talks. Experts from Iran and on behalf of the United States, Russia, China, Britain, France and Germany, will confer Wednesday and Thursday on technical details for discussion at next week’s Iran-six power round.