On 28 September 2018, the State of Palestine filed a complaint against the United States before the International Court of Justice (the ICJ, the UN’s Court).
The State of Palestine is denouncing the US embassy’s recent relocation to Jerusalem. The brief filed by the State of Palestine is based on UNGA Res 181 on The Partition of Palestine, adopted in 1947 .
This partition plan provides that the city of Jerusalem, given its broadest definition, does not form part of the two Independent States that were supposed to be created in Palestine. Thus the status of Jerusalem under this plan was a corpus separatum ab ambis statis. As such, the city of Jerusalem cannot be declared to be the capital either state: neither the state of Israel nor the State of Palestine.
The same dispute has already been raised before, in 1980, when Israel adopted a Fundamental Law  which declared Jerusalem as its capital.
At that time, the UN Security Council confirmed through its Resolution 746 that declaring Jerusalem to be the capital of Israel violated the Geneva Convention on Displaced Persons and ordered the State of Israel to repeal this Fundamental Law.
In response to Israel’s denial to repeal the Fundamental Law on Jerusalem, the Security Council went on to adopt Resolution 478 which provides that all UN member states that had established embassies in Jerusalem had to move them. The following countries complied with this order at once: Bolivia, Chile, Colombia, Costa Rica, Ecuador, Guatemala, Haiti, Panama, Holland, the Dominican Republic, Salvador, Uruguay and Venezuela.
The brief filed by the State of Palestine against the US is based on a reasoning that differs from the reasoning articulated in various Palestine bodies till now. The brief is based on the concept defined in UNGA Res 303. This Resolution establishes that, due to its particular religious status, the city of Jerusalem must be internationalized and administrated by the United Nations.