Prime Minister Lee Hsien Loong and two other Cabinet ministers have expressed their condolences following the fatal collision involving United States guided-missile destroyer USS John S. McCain in Singapore territorial waters.

"I was deeply saddened by the loss of lives following the collision between the United States Navy destroyer, the USS John S. McCain, and a merchant vessel east of Singapore on 21 August 2017," PM Lee wrote in his letter to US President Donald Trump yesterday.

"On behalf of the Government of Singapore, I offer my condolences to the victims and their loved ones," he added.

Conveying their condolences separately to their US counterparts - Secretary of Defence James Mattis and Secretary of State Rex Tillerson - Defence Minister Ng Eng Hen and Foreign Minister Vivian Balakrishnan have pledged to render assistance and support to the US Navy and US service personnel.

Ships and aircraft from five nations - Singapore, Malaysia, Indonesia, the US and Australia - were searching for missing US sailors near the site where USS John S. McCain collided with a bigger vessel, the Alnic MC oil tanker.

Five people were injured and 10 crew members of the US destroyer were initially reported missing soon after the incident.

On Tuesday, US Navy and Marine divers found human remains inside sealed sections of the damaged hull of the US warship, which is now moored at Singapore's Changi Naval Base.

Another body, found by the Royal Malaysian Navy about 8 nautical miles north-west of the collision site, has been handed over to the US Navy for identification.