This is the impressive moment a US military helicopter carries out a mid-air refuelling drill off the coast of California.

Footage shows an HH-60W Jolly Green II receiving fuel from an HC-130J Combat King II during an air-to-air refuelling operation.

The manoeuvre was conducted over the ocean as part of Exercise Steel Knight 25 on December 7, with the helicopter flying in close formation alongside the fixed-wing aircraft as fuel was transferred.

Officials said the operation highlights the precision and coordination required for helicopter refuelling during joint military training.

They added that the exercise is designed to strengthen the ability to safely move joint personnel and equipment in support of operational objectives.

Steel Knight is a large-scale joint exercise focused on improving interoperability, increasing readiness, and enhancing coordination across the battlespace.