The West has been sending Ukraine a lot of weapons - SAM’s and ATGM’s - that are great at stopping an enemy offensive. But they have much more limited value for offensive operations. For that, you need more aircraft, and more armored vehicles. Otherwise, your counterattacks/advances are basically limited to foot speed, and it’s thought to get the enemy off balance that way.
Maybe he should ask Putin for a return of the RT-23 missiles they gave up. They can get them back by rail.