A regular serviceman from the Singapore Armed Forces (SAF) has died in Oklahoma, USA after he was found motionless along a lake.

First Warrant Officer (1WO) S. Thivvianathan was on a self-paced run along the Old Cedar Lake on Sunday afternoon (US time) with other servicemen, the Ministry of Defence (MINDEF) said in a news release.

The 51-year-old regular was found at about 4pm US time by a local resident, who performed CPR on him. He was subsequently evacuated by ambulance to the nearby Reynolds Army Community Hospital, and pronounced dead there.

LTC Leow Poh Meng, Commanding Officer of SAF Transport Hub (West), said: "1WO Thivvianathan was well regarded by his peers and superiors. To his men, he was a mentor and a friend."

1WO Thivvianathan, a transport supervisor, was in Oklahoma as part of an advance logistics party which arrived on October 1, in support of SAF training there.