SINGAPORE - The Singapore and United States navies launched a joint maritime warfare exercise on Monday.

About 1,400 soldiers and several battleships, submarines and aircraft from the Republic of Singapore Navy and the United States Navy and Marine Corps are involved in the 12-day exercise.

The 21st annual Singapore-US Cooperation Afloat Readiness and Training (Carat) exercise aims to sharpen conventional maritime warfare capabilities such as anti-air, anti-surface and anti-submarine operations.

Republic of Singapore Navy Fleet commander Lew Chuen Hong and the US Navy's Commander Logistics Group Western Pacific Charles Williams, were both at the opening ceremony at Changi Naval Base on Monday morning.

For the first time, both navies will launch their Unmanned Aerial Vehicle (UAV) systems for conventional maritime warfare operations.

The RSN will deploy its ScanEagle UAV from the decks of the missile corvettes RSS Vigour and RSS Valour, while the USN's FireScout UAV will be launched from the Freedom-class littoral combat ship USS Fort Worth.

Rear-Admiral Lew, in his opening address, said the joint exercise had provided both navies with "invaluable training and enhanced interoperability".

"I believe that it is this close friendship and deep mutual understanding that form the basis of trust."

Rear-Admiral Williams said Exercise Carat, which started in 1995, reflects the maturity of this relationship.