By Marcus George
DUBAI (Reuters) - Iran's supreme leader accused the West on Sunday of lying about his country's nuclear plans in order to cover up their own problems, in a fiery speech that gave no indication he was ready to compromise in talks with world powers.
In an address marking the 23rd anniversary of the death of his predecessor Ruhollah Khomeini, Ayatollah Ali Khamenei warned Israel that any attack on Iran would be answered with a "thunderous blow".
Khamenei - who has total command over Iran's nuclear policy - has publicly forbidden the development of nuclear weapons, but western nations suspect that Tehran is developing in isolation each of the components required for an atomic bomb capability.
"What Americans and westerners do is idiotic. They magnify the nuclear issue to cover up their own problems," Khamenei said, referring to the economic gloom in the U.S. and Europe.
"They are deceitfully using the term nuclear weapons."
Israeli talk of military strikes showed it felt vulnerable after the fall of former Egyptian President Hosni Mubarak, a U.S. and western ally, last year, Khamenei said. "If they take any miscalculated action, they will receive a thunderous blow."
On Saturday a senior military commander said Iranian missiles could reach all parts of Israel and threatened U.S. bases in the region if Iran was attacked.
While Iranian officials maintain a defiant tone, Iran has returned to talks with world powers after the West severely tightened sanctions, targeting its oil exports and isolating its banks, to pressure Tehran to curb what it believes is a bid for nuclear arms capability.
U.S. Secretary of State Hillary Clinton played down Khamenei's comments, saying she did not think they had any bearing on the next round of talk between Iran and the United States, Russia, China, Britain, France and Germany, scheduled for June 18-19 in Moscow.
"I don't draw any conclusions from that statement with respect to the potential success of the talks in Moscow," Clinton told reporters in Stockholm.
"We look forward to seeing what the Iranians actually bring to the table in Moscow. We want to see a diplomatic resolution," she said. "We now have an opportunity to achieve it and we hope it is an opportunity that is not lost, for everyone's sake."
Diplomats say that at the last talks, in Baghdad on May 23-24, Iranian negotiators were more forthcoming than before, and believe Khamenei has given his negotiating team a wider hand to explore a deal.
During his address, Khamenei said that sanctions were not hampering Iran and were "deepening Iran's hatred towards the West".
Iran maintains it will not give up what it says is its right to establish a peaceful nuclear program but has at times appeared flexible to curbing high-grade uranium enrichment that is the West's most pressing concern.
(Additional reporting by Arshad Mohammed in Stockholm; Editing by Robin Pomeroy)