fire support element
Military term for a unit that provides fire support, such as artillery or close air support, to ground forces.
The fire support element provided cover for the infantry on the front line.
火力支援 refers to fire support in general, while 火力支援部隊 specifically denotes the unit or element that provides it.
Compound of 火力 (firepower) + 支援 (support) + 部隊 (unit, element).