The Syrian government and its opponents have rejected a declaration by Syrian Kurds of a federal region in northern Syria, the Associated Press reports.

A statement issued by the Syrian Foreign Ministry says the declaration made in the town of Rmeilan in Syria's Hassakeh province Thursday, March 17 is unconstitutional and worthless.

It warned against any attempt to encroach upon the integrity of Syrian territories.

The Syrian National Coalition, one of the main Syrian opposition groups, also said it rejects such unilateral declarations and warned of any attempt to form autonomous regions that "confiscate the will of the Syrian people."

The statements came after the Syria's main Kurdish faction, the Democratic Union Party, declared a federal region in Kurdish-controlled areas in northern Syria, AP says.