The 45-year-old nephew of the Dalai Lama was struck and killed on Monday night on Florida's coastal highway on the first leg of what was to be a 300-mile (480-km) walk to draw attention to the plight of Tibet, authorities said.
Jigme K. Norbu of Bloomington, Indiana, was pronounced dead at the scene, according to the Florida Highway Patrol.
Norbu was walking after dark along the edge of highway A1A, which extends the length of Florida's east coast, when he was hit by a passing vehicle.
According to the Ambassadors for World Peace website, Norbu had walked or biked more than 7,800 miles across the United States and abroad to raise awareness of what pro-Tibet groups describe as the suppression of Tibetans by Communist China.
Many Tibetans chafe under Chinese rule and the poor and remote region, torn by ethnic tensions, was the site of bloody protests in 2008.
Beijing has blamed exiled Tibetan spiritual leader the Dalai Lama for instigating violence, charges he strongly denies.
The Ambassador for World Peace website, http://www.ambassadorsforworldpeace.org/, chronicled Norbu's arrival on Sunday in St. Augustine in northeast Florida and a celebratory dinner on the night before the planned walk to West Palm Beach.
Neither the driver of the vehicle that struck Norbu, Keith O'Dell, 31, of nearby Palm Coast, nor his 5-year-old son who was traveling with him, was injured.
The accident remains under investigation and no charges have been filed.