U.S. Secretary of State John Kerry broke his right leg in an accident while cycling a portion of the Tour de France route near Scionzier, France, on Sunday and is returning to the United States, his spokesman said.
He has cancelled visits to Madrid and Paris.
Kerry broke his right femur but the injury is not life-threatening and he is expected to make a full recovery, spokesman John Kirby said. He was taken to Geneva's main hospital after being injured and was in a stable condition.
Kerry, aged 71, is still an avid sportsman and often takes his own bike on official trips abroad.
The accident occurred while he was out cycling the day after meetings with his Iranian counterpart Mohammad Javad Zarif in Geneva to try to overcome obstacles in negotiations on curbing Tehran's nuclear program.
It was not immediately clear how his injury would affect the nuclear negotiations with just a month left before a June 30 deadline for a final agreement between Iran and the United States, Britain, France, Germany, Russia and China.
Kerry was flown by medical helicopter from the scene of the accident after he was stabilised at the scene by a doctor and parademic who were with his motorcade at the time. "He did not lose consciousness," Kirby said.
A senior State Department official said it appeared Kerry hit a curb when the accident occurred. There was no other vehicle involved.
Kerry would now be heading back to his home town of Boston to seek treatment at Massachusetts general hospital, Kirby added.
He had been due later on Sunday to travel to Madrid, his first visit to Spain as secretary of state, to sign a bilateral defense agreement that would allow the U.S. to have permanent use of an air base in Moron, Sevilla.
He had then been due on Monday to fly to Paris for a meeting with Iraqi Prime Minister Haidar al-Abadi and members of a U.S-supported coalition fighting the militant group Islamic State.