Turkish President Recep Tayyip Erdogan on Friday blasted some Arab countries for backing a Middle East plan unveiled by the United States, condemning it as "treason".

"Some Arab countries that support such a plan commit treason against Jerusalem, as well as against their own people, and more importantly against all humanity," Erdogan told his party's lawmakers in the parliament.

President Donald Trump on Tuesday unveiled long-awaited details of a US plan for solving the Israeli-Palestinian conflict, warning it may represent the last chance at statehood for the Palestinians.

Palestinian President Mahmoud Abbas called the peace plan the "slap of the century".

Turkey, a strong advocate of the Palestinian cause, had condemned the plan.

"The United States' so-called peace plan is stillborn," Turkey's foreign ministry had said in a statement.

"This is an annexation plan aimed at killing a two-state solution and extorting the Palestinian territory."

Erdogan today added that Turkey may launch a military operation into Syria's northwestern province of Idlib if the situation in the region is not resolved immediately, as attacks by Russia-backed Syrian government forces raised concern of a new refugee wave to Turkey.

Speaking in Ankara, Erdogan said Turkey could not handle a fresh influx of migrants. On Wednesday, Erdogan had said Ankara was losing patience with the assault and accused Russia of violating agreements aimed at curbing conflict in the region.