The visit is expected to take place next week.
Access to the Arak reactor for UN inspectors is a key step in efforts to allay international concerns about Iran's nuclear program.
The visit was confirmed today as Iranian negotiators met with Olli Heinonen, the deputy chief of the IAEA.
The IAEA says today's talks in Vienna are an attempt to clarify "the open issues associated with the scope and content of Iran's enrichment program."
Iran insists its nuclear program is intended only to produce electricity.
The United States accuses Tehran of covertly trying to build nuclear weapons.
Battling Nuclear Proliferation
A nuclear-capable, short-range missile on display in Islamabad, Pakistan, in March (AFP)
IS PROLIFERATION INEVITABLE? On June 18, RFE/RL hosted a briefing featuring Henry Sokolski, executive director of the Nonproliferation Policy Education Center. Sokolski discussed the challenges to the global nonproliferation regime and what Western countries can do to strengthen it.
LISTENListen to the entire briefing (about 60 minutes):
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