What is the standard anti tank weapon used by the US army?

artillery shells and landmines.

Weeel Not Exactly----Actually the best anti tank weapon is another tank. The US has the best tank armor and anti armor projectile in the world. Ground forces do have weapons capable of defeating armor. The AT4 is a short range shoulder fired rocket that will defeat some armor. The TOW missile is a very capable anti tank system that can be mounted on a tripod, wheeled vehicle, light armor as well as helicopters. Helicopter and A10 Warthogs (other aircraft also) have very effective anti tank armament available to them.

Landmines are not a very effective anti tank weapon as the are indiscriminate and some what easy to detect with today's counter mine equipment. Artillery does have some anti armor rounds but defeating tanks is not artillery batteries first priority depending on which theatre of operation it is in.