Key questions about Iran’s nuclear program remain unresolved despite two days of talks with UN experts in Tehran about possible weapons efforts.

Requests by the International Atomic Energy Agency (IAEA) to visit a military base at Parchin were denied, and the team failed to agree on framework to resolve questions about Iran’s alleged nuclear weapons-related work.

“It is disappointing that Iran did not accept our request to visit Parchin during the first or second meetings,” IAEA Director-General Yukiya Amano said. “We engaged in a constructive spirit, but no agreement was reached.”