US Secretary of State John Kerry broke his leg in a cycling accident in France on Sunday and will fly back to the United States for treatment, cutting short a European trip.
Kerry, 71, a keen cyclist, was hospitalised in the Swiss city of Geneva after the accident across the border in the French Alps, the State Department said.
The top US diplomat, who had been holding talks in Switzerland on the Iran nuclear crisis, broke his right femur in the accident in Scionzier near Chamonix.
A source in the French local government office said Kerry had wanted to cycle one of the stages of the Tour de France, the challenging Col de la Colombiere mountain pass.
He has had to cancel both a trip to Spain and his attendance at a Paris meeting on the Syria conflict and the Islamic State group, spokesman John Kirby said.
However Kirby said he planned on Tuesday to "remotely" join the Paris talks, which are aimed at reviewing the international coalition's strategy against the IS group.
"The secretary is stable and never lost consciousness, his injury is not life-threatening, and he is expected to make a full recovery," he said in a statement.
"Given the injury is near the site of his prior hip surgery, he will return to Boston today to seek treatment at Massachusetts General Hospital with his doctor who did the prior surgery."
The top US diplomat was flown by helicopter to the Geneva University Hospital after the accident which occurred around 9:40 am (0740 GMT).
"Paramedics and a physician were on the scene with the secretary's motorcade at the time of the accident," Kirby said.
Another State Department official, speaking on condition of anonymity, said Kerry "fell after hitting a curve".
Kerry held talks Saturday in Geneva with his Iranian counterpart Mohammad Javad Zarif as part of international efforts to secure a landmark nuclear deal ahead of a June 30 deadline.
The talks did not go into a second day as planned after Tehran rejected a key Western demand for site inspections.
There are heightened diplomatic moves to try to end a 12-year international standoff and put a nuclear bomb beyond Iran's reach.
The lanky Kerry has become a recognisable figure as a regular globetrotter since taking office as Secretary of State in February 2013.
During breaks from negotiations, he has often headed out of his hotel to ride his bike -- which he usually brings along on his foreign missions -- accompanied by a posse of security guards.
Kerry had been scheduled to leave late Sunday afternoon for Madrid.
Spain and the United States were to formalise an agreement under which Spain will host a permanent force of 2,200 US Marines for deployment on missions to Africa.
"The secretary very much regrets not being able to visit Spain to meet with one of our close allies for discussions on a range of issues, as well as being unable to attend the counter-ISIL coalition ministerial meeting on Tuesday in Paris in person," Kirby said.
"The secretary plans to participate in the counter-ISIL coalition meeting remotely."