The UN only voted to put an opportunity there for the two parties to declare Sovereignty, according to a set of conditions, if the wished. Israel accepted the conditions. Declared it's Sovereign territory and was recognized by the majority of the International Community of States, over riding the Arab States objections. The Arab states did not, they were not obliged to. UNGA res 181 was non-binding. A Declaration of Sovereignty and Sovereign borders are.
Report: Palestinian, 18, killed in clashes with IDF in West Bank (Haaretz)
from the article: Palestinian PM: Declaration of statehood just a formality