The UN nuclear agency has invited its members - including Israel, Arab states and Iran - to attend rare talks later this year about the volatile Middle East and efforts to rid the world of atomic bombs, it said on Friday.

While Israel and some Arab nations have indicated readiness to take part in the planned forum in Vienna in November, Iran said it saw no justification for such a meeting now.

In a letter to Yukiya Amano, the head of the International Atomic Energy Agency, Iran's envoy to the IAEA took a swipe at Israel, widely believed to have the Middle East's only nuclear arsenal.

Nuclear weapons are especially controversial in the Middle East. Arab states often criticize Israel over its presumed nuclear arsenal. Israel and the United States see Iran as the region's main proliferation threat, accusing Tehran of covertly seeking to develop nuclear arms. Iran denies this.

"We are of the view that stability cannot be achieved in a region where massive imbalances in military capabilities are maintained, particularly through the possession of nuclear weapons which allow one party to threaten its neighbors and the region," Iranian Ambassador Ali Asghar Soltanieh wrote.

The letter was made available to Reuters on Friday.

A gathering of regional adversaries around the same table to talk about nuclear arms and disarmament could be symbolically important, even though any substantive progress is likely to remain elusive.

Amano wrote to IAEA member states about attending the November 21-22 forum to debate experience from other parts of the world in establishing zones free of nuclear weapons, such as Africa and Latin America, the UN agency said in a statement.

Participants would "consider how the experience of nuclear-weapons free zones in several regions of the world could be relevant to the Middle East," the IAEA added.

Diplomats stress that no decisions are expected at the planned talks, but that they can be useful as a way to start a dialogue and help build badly needed confidence in the region.

In a report circulated to member states on Friday, Amano said he had sought the views of Middle East countries on the forum's agenda. Twelve Middle Eastern states, including Egypt, Iran, Israel, Saudi Arabia and Syria, had written back.

Small Step

He suggested that his efforts had been broadly welcomed, even though some Arab states proposed changes to the agenda.

Amano "will pursue further consultations with member states of the Middle East region and with other interested parties on arrangements conducive to the Forum being a constructive contribution towards the objective of the establishment" of a nuclear weapons-free zone in the Middle East, the report said.

Amano told Reuters last month he saw "momentum" for his plan to host discussions between Israel and Arab states. IAEA members decided in 2000 that such a meeting should take place but agreement on the agenda and other issues has been lacking.

"A nuclear weapons-free zone in the Middle East will not be achieved tomorrow, everyone knows it, but we can get closer," Amano said in the August 19 interview. "Increasing confidence is very much needed, even a small step is helpful."

Israel is widely assumed to hold the Middle East's only nuclear arsenal and is also the only country in the region outside the nuclear Non-Proliferation Treaty (NPT). Arab states, backed by Iran, say this poses a threat to peace and stability. They want Israel to subject all its atomic facilities to IAEA monitoring.

Israel, which has never confirmed or denied having atom bombs, says it will only join the NPT if there is a comprehensive Middle East peace. If it signed the pact, Israel would have to renounce nuclear weaponry.