With just six days before the deadline, Iran's nuclear talks seem to be faltering as U.S. Secretary of State John Kerry arrived in Vienna on Sunday. 
 
 Kerry had his work cut out for him. As he worked to mend ties with Germany in its espionage dispute with the U.S. and handle the ongoing crisis in Israel and Gaza, Kerry also took on face-to-face meetings with his Iranian counterpart Mohammad Javad Zarif with a ticking clock behind them. By the day's end, no breakthrough had been produced and representatives from the six countries negotiating with Iran said that big hurdles remained. 
 
 The expiration of the interim deal 
 
 After decades of tense relations and mistrust, Iran and the United States (as part of the P5+1 Group) surprised the world by managing to secure an interim deal last fall that would ease sanctions on the Islamic Republic in exchange for suspending work on its nuclear program. July 20 was the date set for the deal to expire. And here we are. 
 
 While there have been some slight hints that discussions could extend beyond the deadline, the P5+1 group seems keen on getting a deal done by July 20. 
 
 As the Associated Press noted: 
 
 Lower-ranking officials represented both Russia and China, possibly reflecting their view even before Sunday that talks past July 20 are unavoidable. But Iranian Deputy Foreign Minister Abbas Araghchi suggested any extension would be relatively short, saying "there is not much willingness" by either side to go a full six months. He, too, earlier spoke of "huge and deep differences." 
 
 "There is a huge gap" 
 
 As reported, several gaps remain between the six countries and Iran, including major questions about the level to which Iran can enrich its uranium. Today, things got interesting. 
 
 Word started to spread about a speech given several thousand miles east of Vienna, in which Iran's Supreme Leader Ayatollah Ali Khamenei emphasized the need for Iran to enrich its uranium capacity at the very moment that the Iranian nuclear delegation and the P5+1 Group were bargaining to reduce it. 
 
 As the news broke, the words "scuttle" and "undermine" began floating: 
 
 Basically looks like Khamenei cut Zarif and co at the knees: http://t.co/9CMVgKD6dX — Jordan Hirsch (@jordanchirsch) July 14, 2014 
 
 Classic Khamenei: 1) Express support for negotiations 2) Undermine negotiators by setting impossible red lines. http://t.co/7dhb5BIzO9 — Karim Sadjadpour (@ksadjadpour) July 14, 2014 
 
 Does Iran want a deal? 
 
 Are these negotiating tactics or reluctance? As Gerald Seib points out (paywall), while the U.S.-led sanctions imposed by the international community had a pretty devastating bite, all the jockeying in Vienna is for naught if Iran doesn't want a deal: 
 
 But there is a difference between wanting a deal and considering one essential. Would economic relief be simply convenient, or does Iran consider failure to achieve it an existential threat to the regime? The negotiations won't succeed unless Iran wants a deal more than its international interlocutors do. And there's probably no way to know for sure exactly how much urgency Iran attaches to a deal until talks reach their 11th hour. 
 
 We'll find out soon enough. ||||| VIENNA (AP) — The top U.S. and Iranian diplomats searched Monday for a breakthrough in nuclear talks, their efforts complicated by crises across the Middle East and beyond that have Washington and Tehran aligned in some places but often opposed. 
 
 U.S. Secretary of State John Kerry waves as he arrives in front of a hotel where closed-door nuclear talks on Iran take place in Vienna, Austria, Monday, July 14, 2014. Kerry will hold in-depth discussions... (Associated Press) 
 
 Iran's Foreign Minister Javad Zarif, foreground, holds a bilateral meeting with US Secretary of State John Kerry background right, on the second straight day of talks, in Vienna, Austria, Monday July... (Associated Press) 
 
 British Foreign Secretary William Hague, left, meets with U.S. Secretary of State John Kerry at talks between the foreign ministers of the six powers negotiating with Tehran on its nuclear program in... (Associated Press) 
 
 U.S. Secretary of State John Kerry leaves the hotel where closed-door nuclear talks on Iran take place in Vienna, Austria, , Monday, July 14, 2014. Secretary of State John Kerry was deep in discussions... (Associated Press) 
 
 The state of U.S.-Iranian relations was adding a new wrinkle to the long negotiation aimed at curbing the Islamic republic's uranium and plutonium programs. 
 
 While the two sides are arguably fighting proxy wars in Israel, Gaza and Syria, they're talking cooperation in Iraq and Afghanistan. And, perhaps in a first, the nuclear matter is battling for full attention. 
 
 U.S. Secretary of State John Kerry and Iranian Foreign Minister Mohammed Javad Zarif spoke for about two hours around midday Monday, the second day of talks in Vienna. They gathered again in the afternoon, hoping to make progress before Sunday's initial deadline for a comprehensive nuclear agreement. An extension of the deadline is possible, though there are opponents of that idea on both sides. 
 
 "We are in the middle of talks about nuclear proliferation and reining in Iran's program," Kerry told U.S. Embassy staff in Vienna during a break in the conversations. "It is a really tough negotiation." 
 
 But other matters were being discussed, too, including Afghanistan, where Kerry visited before Vienna to broker a power-sharing agreement between rival presidential candidates and a full audit of their contested election. 
 
 As the two diplomats sat down Sunday, Zarif called Kerry's Afghan mediation "extremely important" for the Afghan people and echoed the need "to ensure the national unity of Afghanistan and prevent its breakup." 
 
 "We agree," Kerry said. "And it's good to begin with an agreement." 
 
 But even as the U.S. and Iran have recently found increasing areas for cooperation, such as stemming a flow of Sunni extremists into Iraq, they remain diametrically opposed elsewhere. 
 
 The U.S-Iranian regional divide was underscored Monday as the Israeli military downed a drone launched by Gaza militants — the first such unmanned aircraft encountered since the start of the Jewish state's offensive last week. 
 
 Iran is Hamas' primary benefactor and the presumed source of its newfound drone capacity. Washington provides billions in aid each year to Israel. 
 
 The State Department didn't say if Kerry and Zarif broached the escalating Israeli-Palestinian violence or the civil war in neighboring Syria, where the U.S. is providing political and military support to moderate rebels fighting President Bashar Assad's Iranian-backed government. 
 
 But one change appeared clear in this week's talks. Unlike in years past, where U.S.-Iranian interaction appeared largely limited to nuclear matters, the two countries' interests now crisscross at multiple levels, and their discussions are broader. 
 
 Nevertheless, American officials said Kerry was focused on tackling the many differences between the U.S. and Iran on nuclear matters. His goal is to gauge "Iran's willingness to make the critical choices it needs to make," according to a senior State Department official. 
 
 The official wasn't authorized to be quoted by name and demanded anonymity. 
 
 Monday's talks came a day after Kerry and the foreign ministers of Britain, France and Germany failed to reach a breakthrough with Iran on uranium enrichment and other issues standing in the way of a deal that would curb Iran's nuclear program in exchange for the end of nuclear-related sanctions on Tehran. Each official cited significant gaps. 
 
 Iran says it needs to expand enrichment to make reactor fuel and insists it does not want atomic arms. But the U.S. and others fear Tehran could steer the activity toward manufacturing the core of nuclear missiles. Washington is leading the insistence on deep enrichment cuts. 
 
 Under a six-month interim agreement that went into effect in January, world powers and Iran have until July 20 to conclude a final deal. The goal for the West is a long-term agreement setting clear limits on Iranian activity and locking in place an international monitoring regime to ensure that the Islamic republic cannot develop nuclear weapons. 
 
 The interim arrangement also offers the option of an additional six-month period for negotiations, an extension that appears increasingly likely. Officials have suggested they may agree on a shorter window, however. 
 
 In Washington, White House spokesman Josh Earnest wouldn't say whether President Barack Obama had authorized Kerry to extend the deadline if necessary. 
 
 "To its credit, Iran has defied the expectations of some," Earnest said, by fulfilling some of the steps it agreed to take. But he said on other key issues Iran hasn't yet made the decisions needed to prove the world its intentions are peaceful. "That's ultimately where the gaps remain," he said. 
 
 For the U.S. and Iran, an extension makes sense in multiple ways. With so much at stake, and the potential for U.S.-Iranian cooperation in other areas being explored, neither side wants to terminate the nuclear talks. Such a course could put Tehran back on a path toward isolation and even set the stage for U.S. military action if Iran proceeded again toward nuclear weapons capacity. 
 
 Even if their interests in continuing nuclear talks align, both face difficult internal pressures against a deal — or an extension for that matter. 
 
 Iranian hardliners oppose almost any concession by President Hassan Rouhani's government. In the U.S., some lawmakers have threatened to scuttle any emerging agreement if it would allow Iran to maintain some enrichment capacity. 
 
 A letter being circulated in Congress by Sens. Bob Menendez, D-N.J., and Lindsey Graham, R-S.C., emphasizes that a lessening of U.S. sanctions should be conditional on the nuclear agreement making tough demands on Iran. 
 
 These would include international inspections lasting for a minimum of two decades and full disclosure by Iran of any military aspects of its nuclear program.
– A Sunday deadline is looming for Iran to strike a nuclear deal with six world powers under a plan set in motion last year—but with just days to go, Iran's supreme leader has made the chances of a deal being forged in time look supremely unlikely. In a major speech, Ayatollah Ali Khamenei said the country will need 190,000 centrifuge machines, 19 times as many as the 10,000 negotiators from the US, France, Britain, Russia, China, and Germany want to limit the country to in order to reduce its capacity to build nuclear weapons. After the leader's speech appeared to undermine negotiators, analysts began to wonder whether Iran really wants a deal that would limit its nuclear capacity in return for the lifting of sanctions, or if Khamenei is playing for time, the Atlantic notes. "In ostensibly expressing support for the Iranian negotiating team, close scrutiny of Khamenei's speech shows that in reality his remarks were aimed at severely curtailing his team's room for maneuver, making it effectively impossible to bridge gaps with the stance" of the six powers, an intelligence analysis seen by Reuters states. If all sides agree, the talks could be extended for another six months, though US officials say they will need to see some progress in the days to come before they will agree to an extension. John Kerry joined the talks in Vienna yesterday, but it's not clear whether he made any progress during hours of talks with Iran's foreign minister; issues including Afghanistan were also discussed, the AP reports.