The Arab League has slammed US President Donald Trump over his decision to recognise Jerusalem as the capital of Israel, calling it a "dangerous violation of international law."
The organisation called on the US to abandon the move and said it would seek a United Nations Security Council resolution rejecting the decision.
In a statement, foreign ministers of the group’s 22 member states said President Trump's Wednesday announcement will lead to increased violence throughout the region.
The group said move had no legal implication and was "void," as its members met for an emergency meeting in Cairo.
President Trump’s endorsement of Israel's claim brings long-standing US policy dictating that the city's status must be decided in talks with the Palestinians to an end.
East Jerusalem has been considered illegally occupied under international law since Israel annexed it in 1967.
Palestinians see the eastern side of the city as the capital of their future state.
In a statement, the Arab League said: "The decision has no legal effect... it deepens tension, ignites anger and threatens to plunge the region into more violence and chaos."
During its meeting, Lebanon's Foreign Minister Gebran Bassil said member states should consider imposing economic sanctions on the US in an effort to force it to reconsider the move – and ensure plans to move the US embassy From Tel Aviv to Jerusalem are not put into action.
He said: "Pre-emptive measures (must be) taken... beginning with diplomatic measures, then political, then economic and financial sanctions."
However the statement did not make any mention of economic sanctions on the US.
The statement marks a change in tone from the praise Washington's traditional Arab allies heaped on Mr Trump at the start of his presidency.
The Cairo meeting follows three days of violent protests in the Gaza Strip and West Bank over President Trump's comments.
Hamas claims two people were killed after Israeli warplanes struck military targets in Gaza.
"We have taken a political decision not meant to reflect (what is going on in) the streets. Political work is responsible work," Arab League chief Ahmed Aboul-Gheit told a news conference.
"Jerusalem has been occupied for 50 years. This is an extended battle, a battle that will be escalated."
Palestinian Foreign Minister Riyad al Maliki insisted there was "complete" unity among the Arab states.
"There were differences in assessment when we moved to specifying measures (against the US)," he said. "But in the end we agreed on gradually escalating measures."