Iran's Supreme Leader Ayatollah Ali Khamenei said on Wednesday Tehran would not accept "unreasonable demands" by world powers during negotiations over its disputed nuclear programme, and ruled out letting inspectors interview its atomic scientists.

The comments, reported on state TV, were the latest in a series of forthright statements on inspections in the countdown to a June 30 deadline to resolve a decade-old standoff over Iran's nuclear work.

"We will never yield to pressure ... We will not accept unreasonable demands ... Iran will not give access to its (nuclear) scientists," Khamenei said according to the state TV report.

Khamenei, who has the final say for Iran on any deal, last month ruled out any "extraordinary supervision measures" over nuclear activities and said military sites could not be inspected. [ID:nL5N0X62L2]

The U.N. International Atomic Energy Agency (IAEA) has been trying to investigate Western allegations that Iran has worked on designing a nuclear warhead. Iran says its nuclear programme is peaceful and that it is working with the IAEA to clear up any suspicions.

Western officials say Iran must step up cooperation with the IAEA if it wants to reach a broader diplomatic deal with world powers that would gradually end crippling financial and other sanctions on the oil producer.

Iran reached a tentative deal with the powers on April 2 to allow U.N. inspectors to carry out more intrusive, short-notice inspections under an �Additional Protocol� to the Non-Proliferation Treaty. But there have been sharply differing interpretations from both sides on the details of that access.

By Reuters