Europe must take a firmer line with Iran over its controversial nuclear programme, Israeli Prime Minister Benjamin Netanyahu said Thursday at the start of a working meeting with EU foreign policy chief Catherine Ashton.

"We need to exert pressure on them. We're not talking about political spin but about the spinning of centrifuges," he said in remarks communicated by his office.

"It must stop and I think it is up to Europe to join the United States and Israel and all the other elements in the international community in demanding a halt to Iran's nuclear programme," he said in what appeared to be a rebuke.

Ashton's visit comes just six days after the election of moderate Hassan Rowhani as Iran's new president in what analysts have said could soothe tensions with the West over Tehran's nuclear programme.

But Israel has refused to be mollified, with Netanyahu earlier this week warning the world not to "be tempted to ease pressure on Iran."

In response, Ashton acknowledged the importance of consulting with Netanyahu about the situation in Iran after the elections, the premier's office said.

"The real test regarding the elections in Iran will be if Iran changes its policy and stops enriching uranium, removes the nuclear material and closes the illegal nuclear facility at Qom," Netanyahu said.

Speaking later on Thursday, Netanyahu said the greatest threat facing Israel "is that the most dangerous weapons in the world fall into the hands of the most dangerous regimes in the world - especially one regime.

"We cannot allow Iran to achieve nuclear weapons," he said at the closing panel of Shimon Peres's Presidential Conference.

"The test is not what they say, but what they do," he continued, and called on the international community to "keep up the pressure and keep to those demands."

Iran has been slapped with successive rounds of UN Security Council sanctions and also unilateral measures by the European Union and the United States.

The sanctions initially only targeted the nuclear and defence industries but then started to hurt the wider economy, causing concern among ordinary Iranians and even the leadership.

Netanyahu also took the opportunity to reiterate that only if Palestinians accepted a Jewish state and the "right of the Jews to live in their ancient homeland as a sovereign people" would a peace agreement be possible.

Earlier in his remarks to Ashton, Netanyahu also urged Europe to take steps to add Lebanon's Hezbollah movement to its list of international terrorist groups.

"I hope that elements in Europe who refuse to declare Hezbollah to be a terror organisation will change their minds and I hope there will be a European consensus on that," he said, describing such a move as "the right thing to do."

So far, the 27-nation bloc has failed to reach agreement on whether to blacklist the Shiite militia, which would subject the group to an asset freeze, with experts meeting on the issue in Brussels on Wednesday.

Britain is openly in favour, but France and Italy are reluctant, fearing a negative impact on Lebanon where Hezbollah is the leading political group, and a possible backlash against the UN peacekeeping force in the south of the country.

Netanyahu and Ashton were also to discuss US peace efforts in a meeting which comes the day after she met Palestinian president Mahmud Abbas in Ramallah.

Netanyahu said that a renewal of direct negotiations without pre-conditions was "the right thing to do" and insisted on Israel's willingness to start immediately. "I hope that president Abbas is also ready," he said.

Direct talks broke down just weeks after they were started in September 2010 in a dispute over settlements.

A Palestinian demand that Israel freeze settlement construction and accept the 1967 lines as the basis for negotiations before resuming direct talks has been rejected by Israel as an unacceptable "pre-condition."

US Secretary of State John Kerry, who arrives in the region next week for his fifth visit since February, has been locked in an intensive bout of shuttle diplomacy in the hope of achieving a breakthrough, although there is no evidence of such so far.