An Iran Air Boeing 747 passenger plane on the tarmac of Mehrabad Airport in Tehran in 2013. Iran bought most of its planes from Boeing before the 1979 Islamic Revolution. The country now has one of the oldest airline fleets in the world. With sanctions lifted, Boeing can once again sell planes to Iran, but the country recently announced a major deal with Airbus. BEHROUZ MEHRI/AFP/Getty Images hide caption

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Construction trailers are suspended in the middle of the 240-foot concrete wall that's been dug below ground level. This area will eventually become the underground parking garage at the hotel. Steve Inskeep/NPR hide caption

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Ahead of a press conference with Premier Matteo Renzi and Iranian President Hassan Rouhani, wooden panels were erected around some Roman statues in Rome's Capitoline Museums. Giuseppe Lami/AP hide caption

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French President Francois Hollande (left) greets Iranian President Hassan Rouhani before a meeting at the Elysee Palace in Paris on Thursday. Rouhani's visit to Europe this week has been accompanied by numerous business deals announced by Iran and European companies. Peugeot-Citroen said Thursday it was returning to Iran to build cars with an Iranian automaker. Christophe Ena/AP hide caption

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The Iranian private airline Mahan Air uses Airbus planes, like the one pictured here at Yemen's Sanaa airport in 2015. Tehran is in talks with Airbus to buy more than 100 additional passenger planes. Hani Mohammed/AP hide caption

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Iranian President Hassan Rouhani opens a book he gave to Pope Francis as a gift at the Vatican on Tuesday. Rouhani is the first Iranian leader to meet with the pope since 1999. With sanctions against Iran falling away, Rouhani also announced business agreements with Italy as part of his visit to Europe. Andrew Medichini/AFP/Getty Images hide caption

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Iranian President Hassan Rouhani (left) meets Italian President Sergio Mattarella at the presidential palace in Rome on Monday. With many international sanctions against Iran lifted, Rouhani has become the first Iranian president to tour Europe since 1999. Gregorio Borgia/AP hide caption

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The words "sherbet" and "sorbet" derive from the Persian sharbat; biryani comes from biryān; and julep started as the Persian gul-āb (rose water), then entered Arabic as julāb, and from there entered a number of European languages, with the "b" softened into a "p." my_amii/Flickr, Jay Galvin/Flickr, Justin van Dyke/Flickr hide caption

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Iranian President Hassan Rouhani presents the draft budget for the next Iranian fiscal year to the chairman of the Iranian Parliament Ali Larijani at the Iranian parliament in Tehran on Jan. 17, 2016. Anadolu Agency/Getty Images hide caption

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Congressman Jeff Duncan displays pictures of Saeed Abedini, Amir Hekmati, Jason Rezaian and Robert Levinson during a House Committee on Foreign Affairs hearing in Washington, D.C. on July 28, 2015. Abedini, Hekmati and Rezaian were freed this weekend as part of a prisoner swap; Levinson's location remains unknown. Anadolu Agency/Getty Images hide caption

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U.S. Secretary of State John Kerry (left) meets with Iranian Foreign Minister Mohammad Javad Zarif (right) in Vienna on Saturday. The International Atomic Energy Agency, or IAEA, has verified that Iran has met all conditions under the nuclear deal. Kevin Lamarque/AP hide caption

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A man reads a flier with a photo of U.S. Marine veteran Amir Hekmati on May 19, 2014, during a vigil held in Lafayette Park across from the White House in Washington, D.C. The vigil was held on the 1,000th day of Amir's imprisonment in Iran. Hekmati was set to be released Saturday as part of a prisoner exchange. Karen Bleier/AFP/Getty Images hide caption

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Ali Rezaian, brother of Washington Post Tehran Bureau Chief Jason Rezaian (shown in picture frame), talks about his brother's imprisonment in Iran while testifying before the House Foreign Affairs Committee on June 2, 2015. Iranian media outlets are reporting that Rezaian has been released. Chip Somodevilla/Getty Images hide caption

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Rescuers search through the rubble of the U.S. Marine barracks Oct. 23, 1983, in Beirut, Lebanon, after a suicide truck bombing. The blast — the single deadliest attack on U.S. forces abroad since World War II — killed 241 American service members. The Supreme Court is deciding whether Congress can pass a law compensating the victims, and those of other attacks, using Iranian government funds. Jim Bourdier/AP hide caption

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This 2011 photo shows the heavy water nuclear facility near Arak. International sanctions relief will be triggered when Iran follows through on commitments to reduce its nuclear program. Hamid Foroutan/AP hide caption

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