Vienna: The UN's nuclear watchdog agency said today that a team of inspectors would visit a heavy-water Iranian reactor next week to address concerns over Tehran's disputed nuclear programme.

Olli Heinonen, deputy director general of the International Atomic Energy Agency (IAEA), told journalists that the inspectors would visit the plutonium-producing reactor under construction at Arak either today or tomorrow.

Heinonen was speaking after talks in Vienna with Iran's deputy national security chief Javad Vaeidi and IAEA ambassador Ali Asghar Soltanieh on finalising a plan to clarify "open issues associated with the scope and content of Iran's enrichment programme." "We had good discussions. We made constructive progress," Vaeidi told reporters. "The next meeting will be at beginning of August in Tehran."

Iran said on July 3 that it would let IAEA inspectors visit the Arak reactor.

The UN Security Council has imposed two rounds of sanctions to get Tehran to cease enriching uranium, to stop building Arak and to cooperate fully with IAEA inspectors and there are calls for a third round.

Several diplomats have warned that Iran, by allowing inspections of Arak, might just be stalling in order to avoid more sanctions.

Iran has rejected any halt in its enrichment work, insisting that its nuclear activities are peaceful effort to generate electricity. The United States has led international charges that it is hiding a covert nuclear weapons programme.