Rule 130 of the Geneva Convention states that a conquering army not deport or transfer parts of their own civilian population into a territory they occupy. But this rule applies specifically in cases of occupying a sovereign country. Since the “West Bank” annexation by Jordan was never ratified by the UN, the IDF, which is today the sovereign there, is not considered an occupying power, but rather a caretaker power. As such it is empowered to move civilian populations into the area under its government.
The notion of a Palestinian State in part of the “West Bank” was never recognized by the U.S. until President GW Bush mentioned it in 2003. Until that time, the U.S. was only supporting a Palestinian Autonomy under Israeli rule.