WASHINGTON – US Secretary of State John Kerry underwent hours of surgery on Tuesday in his hometown of Boston after breaking his femur in a bicycle accident over the weekend.While the secretary’s team says that Kerry is committed to an “aggressive, ambitious and responsible” recovery schedule, White House press secretary Josh Earnest said on Tuesday that the Obama administration could not say how long he would need to recover before doctors deemed him fit to fly.“It’s too early to say,” Earnest said, speaking to reporters moments after Kerry’s operation ended.Negotiations with Iran over its nuclear program have long taken place on neutral ground: either in Switzerland, along the banks of Lake Geneva in and around United Nations facilities, or in Vienna, which hosts the UN’s International Atomic Energy Agency.But over two years of negotiations, talks have occasionally taken place on the sidelines of major conferences or assemblies at the UN headquarters in New York. Earnest would not comment on New York as a possible host to the final round of the nuclear negotiations.Still, the possibility has been raised since the secretary hit a curb while riding his bike in Geneva, where he met with Iranian Foreign Minister Mohammad Javad Zarif on Saturday. Kerry, 71, has had hip surgery in the past, not far from the fracture in his right femur.Given his historic, personal relationship with his Iranian counterpart, Kerry is keen on participating inside the room, “personally,” his senior adviser Marie Harf said on Monday. “What that looks like, we’re still working out logistics,” Harf said. “But absolutely, he is committed to moving forward, working toward the end of this month and the deadline, personally.”That deadline, June 30, appeared to be in jeopardy well before Kerry injured himself in France on Sunday: The negotiators are still facing questions of political will, including the pace of sanctions relief and whether Iran is willing to allow inspections at a select number of its military facilities.A New York Times report on Tuesday suggested that, in violation of an interim deal that has governed the negotiating period, Iran has increased its stockpile of nuclear fuel within the last year by 20 percent. The IAEA reported the findings this month without identifying an explanation for the increase, but the Times report claimed the news “complicated” the talks.Speaking with The Jerusalem Post, one US official declined to corroborate that new developments had further complicated the talks based on new reporting from the IAEA.Meanwhile, talks are ongoing at the expert level, with political directors from each participating nation – the US, Britain, France, Russia, China, Germany and Iran – meeting with increasing frequency as the deadline approaches.The US maintains that it is not entertaining an extension in the talks.