Arab foreign ministers late on Saturday urged the United States to abandon its decision to recognize Jerusalem as Israel's capital, saying the move would increase violence throughout the region.

The announcement by President Donald Trump on Wednesday was a "dangerous violation of international law", had no legal impact and was "void", the Arab League said in a statement after a session attended by all its members in Cairo.

Trump's endorsement of Israel's claim to all of Jerusalem as its capital would reverse long-standing U.S. policy that the city's status must be decided in negotiations with the Palestinians, who want East Jerusalem as the capital of their future state.

"The decision has no legal effect ... it deepens tension, ignites anger and threatens to plunge region into more violence and chaos," the Arab League said at 3 a.m. local time after hours of meetings that began on Saturday evening.