Kerry was in stable condition and in good spirits as he prepared to return to Boston for further treatment with the doctor who previously operated on his hip, U.S. State Department spokesman John Kirby said. He said X-rays at a Swiss hospital confirmed that Kerry fractured his right femur.
"The secretary is stable and never lost consciousness, his injury is not life-threatening and he is expected to make a full recovery," Kirby said in a statement.
Kerry, 71, was taken by helicopter to Geneva's main medical center, HUG, after hitting a curb with his bike near Scionzier, France, about 40 kilometers southeast of the Swiss border.
Paramedics and a physician were on the scene with his motorcade at the time and provided him immediate attention. They quickly decided to order the 10-minute-long helicopter transport.
The Dauphine Libere, a local newspaper, said Kerry fell near the beginning of his ride to the famed mountain pass called the Col de la Colombiere, which has been a route for the Tour de France more than a dozen times.
Right around the time of his fall, a Twitter feed about local driving conditions warned of the danger due to gravel along the pass. But U.S. officials said there was no gravel on the road where the accident occurred. According to the newspaper, some Haute Savoie officials were with Kerry at the time, including the head of the region.
Kerry's regular plane was returning to the United States carrying much of his staff and reporters who accompanied on the trip.
The secretary of state planned to fly back late Sunday aboard a plane with special medical equipment "to ensure he remains comfortable and stable throughout the flight," Kirby said. "Its use is nothing more than a prudent medical step on the advice of physicians."
Kerry's cycling rides have become a regular occurrence on his trips. He often takes his bike with him on the plane and was riding that bicycle Sunday.
During discussions in late March and early April between world powers and Iran, Kerry took several bike trips during breaks. Those talks were in Lausanne, Switzerland, and led to a framework agreement.
Kerry had been in Geneva for six hours of meetings with Iranian Foreign Minister Muhammad Javad Zarif on Saturday as the sides now work to seal a comprehensive accord by June 30.
The prospect of a lengthy rehabilitation could hamper the nuclear talks and other diplomatic endeavors. Even if Kerry does not need surgery, it was not immediately known when he could fly again after returning to the United States.
Kerry has been the lead negotiator in several marathon sessions with Iran going back to 2013. The injury could affect other potential trips, such as one to the Cuban capital to raise the flag at a restored U.S. Embassy.
As for the current trip, Kerry had planned to travel to Madrid on Sunday for meetings with Spain's king and prime minister, before spending two days in Paris for an international gathering to combat IS.
He will participate in the Paris conference remotely, Kirby said.
Kerry decided to seek treatment at Massachusetts General Hospital because the fracture is near the site of his earlier hip surgery, Kirby said.

***
Iraqi Volunteers Lead Push to Retake Ramadi
HABBANIYAH, Iraq (Dispatches) -- Iraqi forces have seized from ISIL militants a string of hamlets and villages in the dust-choked desert southeast of Ramadi in recent days, closing in on the key city for a counteroffensive.
But the yellow-and-green flags that line the sides of the newly secured roads and flutter from rooftops leave no doubt as to who is leading the fighting here: Kitaeb Hezbollah.
While Shia volunteers have spearheaded the fight elsewhere, the Iraqi army and counterterrorism units had been on the front lines in Anbar province.
But with the fall of Ramadi, the province’s capital, this month, paramilitary forces are now taking the upper hand. They include groups such as Kitaeb Hezbollah, responsible for thousands of attacks on U.S. soldiers who fought in Iraq after the 2003 invasion.
Until recently, the Iraqi government had held back from ordering Iraq’s popular mobilization units, a mix of Shia militias and volunteers that formed last summer, to Anbar. Authorities were concerned that sending them to battle in a Sunni majority province could provoke sectarian conflicts. But Prime Minister Haider al-Abadi dispatched them when regular forces crumbled in Ramadi and local politicians asked for the units’ help.
Now Shia militias including the Badr Organization are pressing toward the city from the northeast, in an operation its commanders claim to be planning and leading. Meanwhile, a push to flank Ramadi from the southeast is dominated by Kitaeb Hezbollah.
At the Iraqi army base in Habbaniyah, about 20 miles from Ramadi, Maj. Gen. Qasim al-Muhammadi, the head of Anbar Operations Command, explained that the Iraqi army and the militias are fighting "side by side”. Outside, Kitaeb Hezbollah flags flew just feet from his office.
Although army commanders in Anbar say they are still leading the fight, militiamen contend otherwise. Tribal forces in the area are also being armed, with 800 fighters attending an enrollment ceremony in Habbaniyah last week. But they complain that the process has been slow.
"We liberated this area five days ago, and now the army is helping us hold the ground,” said Zaid Ali Sudani, a turbaned Kitaeb Hezbollah fighter from Basra in southern Iraq, who was guarding a defense line last week near the village of Ankour, south of Ramadi. "We wish the army could be at the same level as the (popular mobilization units),” he said. "In reality, they are much weaker.”
The fall of Ramadi has damaged Iraqis’ confidence in the United States.  
Disillusionment with the U.S. government is evident in Habbaniyah. Falih al-Essawi, deputy head of Anbar’s provincial council, was waiting to meet the army chief Thursday. He was still seething about the fall of the city.
"I was the first ally of the United States in Anbar,” he railed. "But the big man lied and said Ramadi wouldn’t fall.”
Anbar had two choices on an ally, he said — the United States or Iran.
"We chose America, we chose a strong country, but we were wrong,” Essawi said.