VIENNA – The United States made “tangible progress” in direct negotiations with Iran, US Secretary of State John Kerry said on Tuesday, before departing Vienna with no plans to return before next week’s deadline for the end of talks over Iran’s nuclear program.The talks are likely to be extended beyond the July 20 deadline, which is allowed under an international agreement that jump-started the diplomatic effort. But speaking to the press, Kerry alluded to a debate surely awaiting him in Washington: Over the merits of such an extension, based on what has thus far been achieved in the Austrian capital by diplomats from the world’s most powerful nations.In an interview with The New York Times on Monday, Iranian Foreign Minister Mohammad Javad Zarif suggested that Iran was still unwilling to dismantle any of the infrastructure in its nuclear program that had alarmed the international community.The most Iran is willing to do, Zarif said, is cap the program and its production, for up to roughly seven years.Canceling a trip to the Middle East to broker a cease-fire between Israel and Hamas in Gaza, Kerry instead returned to Washington for consultations on the Vienna negotiations, after meeting with Zarif three times in as many days. His briefings to US President Barack Obama and leadership in Congress will address “the prospects for a comprehensive agreement, as well as a path forward if we do not achieve one by the 20th of July,” he said, “including the question of whether or not more time is warranted, based on the progress we’ve made and how things are going.”America’s goal in the negotiations remains, he said, “not just to declare that they will not obtain a nuclear weapon, but to demonstrate in the actions they take beyond any reasonable doubt that any Iranian nuclear program, now and going forward, is exclusively for peaceful purposes.”Senate Foreign Relations Committee chairman Robert Menendez (D-NJ) took to the floor of the Senate on Tuesday to discuss the matter, describing "Let’s be clear – this would leave 19,000 centrifuges spinning in Iran," Menendez said. "That is not an endgame. It’s a non-starter."“The Zarif proposal would extend the Joint Plan of Action, allowing Iran’s nuclear program to run in place subject to inspections, but make no concessions – none – not a single concession that would demonstrably setback Iran’s nuclear ambitions in the long-term," Menendez continued, calling a proposal built of such terms "unacceptable."Even before Kerry landed, however, the debate had already begun: House Foreign Affairs Committee chairman Ed Royce (R-California), as well as ranking member Eliot Engel (D-New York) , both issued statements airing concern over what they characterized as a lack of progress.The Iranian government had made clear that they were unwilling to dismantle its nuclear program, Royce said, calling on the Obama administration to “finally engage in robust discussions with Congress about preparing additional sanctions against Iran.” The committee chairman announced a series of hearings on Iran on Tuesday – not just on its nuclear program, but on its efforts to “destabilize the Middle East.”“Zarif appears to be saying that the Joint Plan of Action should be considered [as] a comprehensive deal, and that Iran should be free to produce unlimited amounts of enriched uranium after a relatively short period of time,” Engel said in a statement, adding that his proposal “doesn’t give negotiators much to work with.”The White House said Kerry’s purpose in Vienna was to gauge whether Iran is serious about pursuing a comprehensive nuclear deal that would bring Iran in line with its international obligations, as prescribed by the Nuclear Nonproliferation Treaty, which world powers said Iran has violated for more than 10 years.“We have always said that if we can make some significant progress, that if we thought we needed some additional time, we thought the world would probably want us to take it, and to get to a final agreement,” one senior administration said from Vienna on Saturday.Delegations from the United States, United Kingdom, France, Russia, China, Germany and Iran expect to remain in Vienna for negotiations until next week’s deadline.