Infantry battalions are the heart and soul of the ground combat element. The mission of locating, closing with, and destroying the enemy with fire and maneuver and repelling the enemy's assault with fire and close combat lies with the "grunts". Marine infantry battalions often have limited organic equipment outside of small arms, infantry crew-served weapons (e.g., heavy machine guns, medium mortars, and anti-tank missiles), and a few light tactical trucks. Marine infantry primarily maneuvers by foot as light infantry, and must be supplemented with additional trucks to become motorized infantry or Amphibious Assault Vehicles to become mechanized infantry.