Diplomats insisted they are closing in on an agreement to curb Iran's nuclear programme despite the failure to clinch a long-sought deal in marathon negotiations in Geneva.
As Tehran said it would not abandon its "right" to enrichment, Israeli Prime Minister Benjamin Netanyahu said Israel would do all it could to keep the so-called P5+1 group of world powers from striking a "bad and dangerous" deal.
American Secretary of State John Kerry defended US negotiations with Iran, saying Washington is "not blind" and is keeping Israel's best interests at heart, ahead of a visit by UN nuclear chief Yukiya Amano to Tehran on Monday.
Hopes for a deal had soared after top diplomats rushed to Geneva to join the talks, but faded again as cracks began to appear among world powers when France raised concerns over a heavy water reactor being built at Arak. The talks ended in the early hours of Sunday.
But diplomats on Sunday insisted they were zeroing in on an agreement to lift some of the crippling sanctions on Iran in return for the freezing of much of its nuclear programme, and planned to meet again from November 20.
Russian Foreign Minister Sergei Lavrov said Tehran had been "decisive" in the "very substantial" talks aimed at renouncing "threats and sanctions".
His British counterpart William Hague -- who also attended the three days of talks in Geneva -- said it was "vital to keep the momentum" and insisted "a deal is on the table and can be done".
Japanese Foreign Minister Fumio Kishida urged Iran to take further steps to clinch a nuclear deal in a meeting with President Hassan Rouhani in Tehran on Sunday.
Kishida "suggested" Iran accept the Non-Proliferation Treaty, which allows unannounced inspections of its nuclear sites, said a Japanese spokesman.
The pause in talks has given a window of opportunity for opponents, particularly Israel, to derail the deal. Israel sees Iran's nuclear programme as a threat to its existence.
The short-term deal would have reportedly frozen or curbed some of Iran's nuclear activities, which Israel and the West suspect are aimed at developing the ability to build a nuclear weapon.
Iran, which insists its programme is entirely peaceful, would receive limited relief from sanctions battering its ailing economy while the two sides worked on a comprehensive agreement.
Israel -- the region's sole if undeclared nuclear-armed state -- fears an agreement would remove sanctions while allowing Tehran to enrich uranium and advance work on the plutonium reactor at Arak.
On Sunday, Netanyahu told CBS television that "Iran gives practically nothing and it gets a hell of a lot".
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"That's not a good deal. I hope -- I can only express my wish -- that the P5+1 (Britain, France, the United States, Russia and China plus Germany) -- use the time to get a good deal that takes away Iran's nuclear military capability," he said.
The hardline Iranian Kayhan newspaper warned "rushing into an agreement would prompt the enemies to think Iran... is ready to give major concessions".
Rouhani sought to allay such concerns as he pleaded for the conservative-dominated parliament's support.
"There are red lines that must not be crossed," ISNA news agency quoted him as saying.
"The rights of the Iranian nation and our national interests are a red line. So are nuclear rights under the framework of international regulations, which include enrichment on Iranian soil."
Kerry offered assurances about the US position, saying Washington is "not blind, and I don't think we're stupid," insisting there is "zero gap" between the White House and its commitment to Israel.
Kerry, in Abu Dhabi Sunday, dismissed the idea that a row with French Foreign Minister Laurent Fabius had derailed the Geneva talks at the last minute, while also rejecting criticism Washington was abandoning key allies.
"A number of nations -- not just the French, but ourselves and others -- wanted to make sure that we had the tough language necessary" he told NBC's "Meet the Press".
However, conservative US leaders, fond of finger-pointing at France in recent years, lavished praise on Paris for blocking an agreement.
"Vive la France!" tweeted Senator John McCain, an outspoken voice on national security issues.
Diplomats have seen a window of opportunity for the decade-long nuclear talks following this year's election of Rouhani, a reputed moderate who vowed to engage with the West.
Rouhani hopes to see the lifting of US and European sanctions that have more than halved Iran's oil exports, created serious obstacles in repatriating petrodollars and provoked rampant inflation.
One of the main stumbling blocks in the most recent talks was the Arak reactor, which would eventually give Iran a second route to an atomic bomb by producing plutonium as a by-product.
Foreign Minister Mohammad Javad Zarif did not rule out further talks over the reactor.
The final say on Iran's nuclear work rests with supreme leader Ayatollah Ali Khamenei, who had expressed support for Iranian negotiators but also voiced pessimism about a breakthrough, citing decades of hostility and mistrust.