Why the US does not allow Ukraine to use its weapons to attack deep into Russian territory
European media said that the US does not want Kiev to move deeper into Russia to re-establish relations with Moscow.

According to RIA Novosti, European media cited anonymous high-ranking US and Ukrainian sources as saying that the US would not allow Kiev to use its weapons to strike deep into Russian territory because it hopes to eventually restore relations with Moscow. In addition, potential Russian targets are out of range of US missiles.
According to media reports, officials in certain parts of the US administration, especially inside the White House, have told the Ukrainian side that the US will eventually want to reset relations with Moscow and asked to refrain from attacking Western weapons deep into Russian territory, as it could undermine efforts to restore communication.
A senior US government source, speaking on condition of anonymity, also said that the use of the Storm Shadow long-range missile or the Army Tactical Missile System may not be as effective as Kiev hopes. The Ukrainian military has limited supplies of missiles and the ones it has may not reach important Russian targets that have been moved out of range.
In mid-July, the Pentagon announced that the United States would not allow Ukraine to use American ATACMS missiles to strike deep into Russia, but that could change. Later, US media reported that the Ukrainian government was pressuring the United States to lift the ban on using ATACMS to strike deep into Russian territory.