Guatemala declared that it would do the same. The editors of the Weekly Standard explain why this matters:

To its opponents, the change in the legal status of certain areas of Judea and Samaria is “annexation;” to its proponents, it is the “extension of sovereignty” or the “application of Israeli law.” Naomi Khan argues that the last term best captures the practical implications of the measures in question. Since the Six-Day War, the Jewish state has continued to uphold the Ottoman legal system in areas of the West Bank under its jurisdiction—despite the fact that the Ottoman empire ceased to exist in 1922; “annexation” would end this situation. Setting aside the usual questions of foreign policy, security, and the possibility of Palestinian statehood, Khan argues that this change would be the one most felt by those who live there: