Carney told reporters covering the president's campaign swing through Florida that Obama had been notified the Jupiter, Fla., police officer had passed away. The West Palm Beach Post reported the officer had been identified as Bruce St. Laurent, a 20-year veteran of the department.
The newspaper said Laurent was struck about 5 p.m. by a pickup truck on an entrance ramp. The truck driver had not been identified.
Carney said the officer was part of the motorcycle escort for the presidential motorcade.
"The accident happened ahead of the motorcade itself and no other vehicle in the motorcade was involved in the accident," Carney said, adding an ambulance that was part of the motorcade was released immediately to assist at the scene.
He said the officer was transported to nearby St. Mary's Medical Center, where he died.