Amidror arrived in Brussels on Monday and met with the EU's deputy secretary general for political affairs Helga Schmid, a spokesman for EU diplomatic service told AFP.

Amidror and Schmid "met as part of regular contacts on a range of topics", spokesman Michael Mann said.

Schmid is responsible for preparatory talks with Iran ahead of the so-called P5+1 group of world powers meeting in Baghdad on Iran's controversial nuclear programme.

The Israeli Haaretz daily had earlier reported that Amidror's trip was linked to concerns in Iran's arch-foe Israel that the upcoming talks could ultimately end with a deal that would allow Tehran to continue enriching uranium.

Israeli officials refused to comment on the report.

The P5+1 grouping of diplomats from permanent UN Security Council members Britain, China, France, Russia and the United States plus Germany held a first round of talks with Iran on April 14 in Istanbul with a second round due to take place in Baghdad on May 23.

Amidror was expected to travel on Wednesday to Berlin where he was to meet German officials, among them Hans-Dieter Lucas, Germany's representative to the Iran talks, the paper said.

Two weeks ago, Amidror was in Moscow for similar talks and met Foreign Minister Sergei Lavrov, Haaretz said.

Israel, widely considered the sole if undeclared nuclear power in the Middle East, has consistently warned that a nuclear-armed Iran would pose an existential threat to the Jewish state, and has refused to rule out a pre-emptive strike in a bid to halt it.

And top officials have expressed doubt the talks would be effective, with Prime Minister Benjamin Netanyahu last month criticising the Istanbul meeting as having little impact, and effectively giving Tehran "a freebie" to continue enriching uranium.

And on Monday, Defence Minister Ehud Barak also said he had little confidence the talks would succeed.

"The P5+1 engagement with Iran, however, does not fill me with confidence. I may sound pessimistic but the state of Israel cannot afford to be duped," he told journalists at a meeting of the Foreign Press Association in Jerusalem.

Israel is concerned that the world powers may cut a deal with Iran that would have only a limited impact on its nuclear programme in exchange for an easing of sanctions, Haaretz said.

"We do not in any way approve the presence of foreign forces in the region. We advise the regional countries against providing a basis for their presence," foreign ministry spokesman Ramin Mehmanparast told reporters.

His comment reinforced criticism voiced on Monday by Defence Minister Ahmad Vahid, who was quoted by the Al-Alam channel as saying: "Such deployments in the region are both harmful and useless. They are mostly done to create a psychological trend and a sense of insecurity in the region."

US officials speaking on condition of anonymity on Monday said an unspecified number of F-22 Raptors had been sent to the Al-Dhafra air base in the United Arab Emirates.

A US Air Force spokeswoman confirmed the presence of the aircraft -- the most advanced fighters in the US arsenal -- in the general region, while a Pentagon spokesman, Captain John Kirby, described it as "a very normal deployment."

The dispatch of the F-22s, though, comes at a moment of high tension in the Gulf.

The United States is leading its allies in a showdown with Iran over its controversial nuclear programme.

While the issue is currently the subject of talks, the next round of which will take place in Baghdad on May 23, Israel and the United States have both warned that military action remains an option should diplomacy fail.

Iran has hit back, saying it could close the strategic Strait of Hormuz at the entrance to the Gulf to oil tanker traffic if it is threatened.

At the same time, Tehran has criticised UAE neighbour Saudi Arabia over its pledge to pump more oil at a time when Iranian oil exports are being cut by Western sanctions.

And Iran and the UAE have been locked in a simmering row over ownership of three islands in the Gulf that both countries claim. Washington has sided with the UAE in that dispute.

In December, the United States announced a $3.48 billion arms sale to the UAE for missile defence batteries and radars.

Two US aircraft carriers and their escort ships are currently in the Gulf.

Mehmanparast said in his briefing: "Regional countries should resort to collective cooperation to ensure their security. Seeking foreign countries or their equipment not only will not provide security but will endanger the region's security."

Vahadi likewise said Gulf countries should cooperate on security, and was quoted as saying: "The presence of foreign forces in the region will only complicate the situation further and lead to insecurity."