A US-Israel ballistic missile exercise postponed until later this year will involve fewer American military personnel than initially planned, the Pentagon has confirmed.

But a US miliary official on Friday rejected a media report portraying the decision as a sign of US mistrust towards Israel.

The exercise is being orchestrated amid rising war talk in the Israeli media and reports that Prime Minister Binyamin Netanyahu and Defence Minister Ehud Barak are debating a unilateral attack to knock out Iran’s nuclear installations.

“Austere Challenge-12 remains the largest-ever ballistic missile defence exercise between our nations and a significant increase from the previous event in 2009,” said Air Force Lieutenant Colonel Jack Miller, a Pentagon spokesman.

“The exercise has not changed in scope and will include the same types of systems as planned,” Miller said. “All deployed systems will be fully operational with associated operators.”

‘Sign of mistrust’

Time magazine had reported on Friday that about 5,000 US troops were originally planned to be involved in Austere Challenge-12 but that the number was being pared back to between 1,500 and 1,200.

The report said Patriot anti-missile systems will arrive in Israel as planned, but the crews to operate them will not. And instead of two Aegis Ballistic Missile Defence warships, the new plan calls for sending just one, and even the remaining vessel is listed as a “maybe”.

It quoted an unnamed Israeli military official as saying the changes were a sign of a lack of trust.

But Miller said US-Israeli ties were strong and Austere Challenge “is a tangible sign of our mutual trust”.

Another US official, speaking on condition of anonymity, declined to say how many US personnel would be involved in the exercise but said the reported figures were wrong and the change in scale was far smaller than indicated in Time.

An Israeli defence official briefed on the exercise told the Reuters news agency the drill “will be held on a similar scale as when it was last held, two years ago”.

The Israeli official said the size of the exercise initially was slated to be larger but added that “the changes are within the framework of the drill’s requirements and nothing more”.

“These things are planned over a long time and changes are not uncommon,” the official said.

Miller said the exercise initially was planned for May but earlier this year Israeli defence officials approached the United States about shifting the date until the late autumn.

“When the exercise was moved, the United States notified Israel that due to concurrent operations, the United States

would provide a smaller number of personnel and equipment than originally planned. Israel reiterated to postpone until late fall,” Miller said.

Vindicated by UN report

Meanwhile, Israeli officials said on Friday that a new UN report adds credibility to their warnings about Iran, as tensions grow between Israel and its allies over how to tackle Tehran’s nuclear programme.

The report by the UN nuclear agency, which emerged on Thursday, concluded that Iran had stepped up the installation of centrifuges capable of making weapons-grade material in an underground bunker at its Fordo underground facility, safe from most aerial attacks.

The UN report also said Iran has effectively shut down inspections of a separate site – the Parchin military complex – suspected of being used for nuclear weapons-related experiments, by shrouding it from spy satellite view with a covering.

It drew rapid criticism from Iranian Foreign Minister Ali Akbar Salehi, who said on Friday the assertion about Parchin “does not make any technical sense”.

Iran denies the West’s claims that it is seeking to develop weapons but its government makes no secret that it sees expansion of its nuclear programme as a right.

An Israeli official said that the UN report “confirms what Prime Minister Netanyahu has been talking about for years now, that the Iranian nuclear programme is designed to achieve a nuclear weapon”.

Israel has been weighing unilateral military action against Iranian nuclear facilities amid faltering international efforts to persuade Tehran to scale back its uranium enrichment, a process that would be key to bomb-making.

The US opposes Israeli strikes. The strain between Washington and its longtime Israeli ally has been on full display this month, with a top US military officer, Gen Martin Dempsey, twice speaking out against a go-it-alone strike.

He was quoted on Thursday as saying he would “not want to be complicit” in such an assault.

Right to nuclear energy

Washington worries that a premature Israeli attack could send global oil prices soaring and touch off a broad conflict possibly drawing in US forces.

Many Israeli officials see US reluctance as linked to the strength of American airpower, which can successfully hit more difficult targets and gives Washington a greater window for action.

But given Israel’s more limited military means, the UN report could reinforce the view there that time for it to act independently is quickly running out.

In his comments to the official news agency IRNA on Friday, Iran’s Salehi said the report wrongly accused his country of trying to clean up traces of nuclear experiments at the Parchin base even though removing radioactive residue would be impossible.

“Whoever has expertise in this field understands that these are offering excuses,” he said. “Such issues cannot be eradicated through cleaning.”

UN officials however have said they never expected to find radioactive residue at Parchin and were looking for other signs of testing.

Ahmadinejad takes notes during the closing session of the Non-Aligned Movement (NAM) summit in Tehran [AFP]

Iranian state television said on Friday that a summit of the 120-member Non-Aligned Movement in Tehran supported its right to the peaceful use of nuclear energy.

But it was not immediately clear whether the text of the conference’s final declaration backed Iran’s claims that its nuclear programme is solely for those peaceful purposes, or simply asserted a general right to produce nuclear energy.

Tehran had been hoping to use the summit to show that it is not isolated diplomatically.

Before leaving the conference, UN Secretary-General Ban Ki-moon told reporters that, as the head of the movement for the next three years, Iran has “a very important opportunity … not only [to] raise their political profile in the international community, but also demonstrate their leadership to exercise a moderate and constructive role in regional and international issues.”

“I have urged the government of Iran to take concrete steps to build international confidence in the exclusively peaceful nature of its nuclear programme,” he said.