* France's Juppe: sanctions on Iran remain a must
* Says Israel must be warned of dangers of military option
* Washington says must see action, not words, from Iran
* Israel warily welcomes new talks between Iran, 6 powers
* Election results signal continued Iranian hard line
By John Irish
PARIS, March 7 France voiced scepticism on Wednesday that a revival of talks between six world powers and Iran would succeed, saying Tehran did still not seem sincerely willing to negotiate about the future of its nuclear programme.
The EU's foreign policy chief, who represents the United States, Russia, China, France, Britain and Germany in dealings with Iran, said on Tuesday they had accepted Iran's offer to return to talks after a standstill of a year that has seen a drift towards conflict in the oil-rich Gulf.
The talks could dampen what U.S. President Barack Obama has called a rising drumbeat of war, alluding to talk of last-resort Israeli attacks on Iran that he and many others worry would kindle a wider Middle East war and hammer the global economy.
French Foreign Minister Alain Juppe, however, raised doubt about what the talks could achieve. "I am a little sceptical ... I think Iran continues to be two-faced," Juppe told France's i-Tele television.
"That's why I think we have to continue to be extremely firm on sanctions (already imposed on Iran), which in my view are the best way to prevent a military option that would have unforeseeable consequences," he said.
Washington, which led a global drive to drastically tighten sanctions on Iran after talks stalled a year ago, said it would not ease the pressure until it sees concrete action from Tehran to address fears it is seeking nuclear arms capability.
"We will demand that Iran live up to its international obligations, that it provides verifiable assurances it is not pursuing a nuclear weapon," White House press secretary Jay Carney said when asked what Washington wanted from the talks.
The United States has succeeded in severely limiting Iran's access to global financial services and secured in extending its own ban on Iranian oil to the European Union and beyond. Carnet said its "dual-track approach" of sanctions and talks would continue.
"We will not relent in our efforts through sanctions and other measures to isolate and pressure Iran. Actions are what matter here and we will judge Iran by its actions," he said.
Iran's Foreign Ministry spokesman called for a more constructive approach ahead of fresh talks.
"The confrontational policy towards Iran has not been fruitful so far and it is better that the relevant officials adopt a constructive interaction instead," Ramin Mehmanparast was quoted as saying by the official IRNA news agency.
Iran has pledged to float "new initiatives" at the talks, whose venue and date are not yet decided, but has not committed itself explicitly to discussing ways of guaranteeing that its nuclear advances will be solely peaceful, as the West demands.
Previous talks have foundered over Iran's refusal to discuss what it deems its "inalienable" right to develop nuclear energy, and recent Iranian comments have not diverged from that line.
"With God's help Iran's nuclear course should continue firmly and seriously. No obstacles can stop our nuclear work," Supreme Leader Ayatollah Ali Khamenei said last month.
The victory in last week's parliamentary election of Khamenei loyalists over backers of President Mahmoud Ahmadinejad, who has seemed more amenable to deals with the West, suggests Tehran's nuclear hard line will not soften soon.
"This shows that Khamenei's stance on foreign affairs and the nuclear issue will be supported by all layers of the system," said analyst Babak Sadeghi.
For Tehran, defiance of "arrogant" Western power has been a useful way to rally domestic support and distract attention from economic difficulties, worsened by sanctions.
"Any deal on nuclear enrichment will harm the prestige of Iranian leaders among their core supporters," said Sadeghi.
Iran denies that its programme to enrich uranium is ultimately meant to yield material for atomic bombs, saying it is for peaceful uses only. But U.N. nuclear inspectors cite intelligence pointing to military dimensions to the programme.
The year-long diplomatic vacuum has been filled by increasingly bellicose rhetoric, Western steps to isolate Iran with severe sanctions and Iranian threats to retaliate by shutting the Strait of Hormuz, the Gulf's oil export channel.
Increasing tensions have spurred a rise in oil prices at a time when many recession-hit countries can ill-afford it.
Western states will tread cautiously in talks, suspicious that Iran's readiness to meet may be a tactic to blunt pressure and buy time for pursuing enrichment in underground plants, not a good-faith effort to reach agreement.
The Islamic Republic made its approach to the six powers at a time when it suffering growing economic pain from sanctions.
Israel is all but convinced that sanctions and diplomacy will not get Iran to rein in its nuclear drive and is speaking more stridently of resorting to military action.
The Jewish state on Wednesday cautiously welcomed the planned resumption of talks with Iran while insisting that any agreement must ensure Tehran does not refine uranium above the 5 percent level suitable for power plants.
"There will be no one happier than us, and the prime minister (Benjamin Netanyahu) said this in his own voice, if it emerges that in these talks Iran will give up on its military nuclear capability," the premier's national security adviser Yaakov Amidror told Israel Radio.
Iran is now enriching uranium to a higher fissile purity it says will be used to run a medical research reactor, but which also brings it much closer to the weapons-grade threshold.
Netanyahu has said Iran must dismantle a subterranean enrichment site near the city of Qom that experts say is designed to survive any air strikes, part of what Israel says is a "zone of immunity" being sought by Tehran.
French President Nicolas Sarkozy was the first among leaders of the six powers to push for tighter sanctions on Iranian oil and finance. Sarkozy said in January that time was running out for efforts to avoid military intervention in Iran.
But Juppe signalled France was wary of resorting to force. "There is still a debate in Israel (about military action) and it's our responsibility to bring to Israel's attention the unforeseeable consequences it would have," he said.
Obama said on Tuesday the new talks with Iran offered a diplomatic chance to defuse the crisis and quiet the "drums of war", although his defence chief said Washington would resort to military action to stop Iran developing nuclear warheads if diplomacy was ultimately judged to be futile.
In Vienna, the 35-nation board of the International Atomic Energy Agency adjourned its week-long meeting until Thursday to give the sextet of world powers more time to agree a joint statement on Iran, diplomats said.