Members of the self defense forces, Feb. 9.

RMEILAN, SYRIA — Syria’s Kurdish-controlled northern regions voted to seek autonomy under a federal system on Thursday, angering both the Damascus government and neighboring power Turkey with a move that could complicate new U.N.-backed peace talks.

The vote to unite three Kurdish-controlled provinces appears aimed at creating a self-run entity within Syria, a status that Kurds have enjoyed in neighboring Iraq since the fall of Saddam Hussein in 2003.

The proclamation is nevertheless an open challenge to many of the sides in Syria’s 5-year-old civil war, as well as their international sponsors, who have mainly been battling for control of what they say must remain a unified state.

The Kurds, who enjoy U.S. military support, have beaten back ISIS fighters to control swathes of northern Syria, but the main Syrian Kurdish party, the PYD, has so far been excluded from peace talks that began this week in Geneva.

Although Washington has backed the Kurds militarily, the State Department said it would not recognize “self-ruled, semi-autonomous zones in Syria”, although it might accept a federal structure if that were the choice of the Syrian people.

The three Kurdish-controlled regions agreed at a conference in Rmeilan in northeast Syria on a system of “democratic self-administration in Rojava and northern Syria”, Kurdish official Idris Nassan said. Rojava is the Kurdish name for north Syria.

“These regions together discussed… the formula for administering these regions,” he said.

Both the government of President Bashar al-Assad and Turkey, a regional heavyweight that is one of Assad’s strongest enemies, were swift to denounce the declaration.

“Any such announcement has no legal value and will not have any legal, political, social or economic impact as long as it does not reflect the will of the entire Syrian people,” state news agency SANA cited a foreign ministry source as saying.

The PYD has consistently said it wants a model of decentralized government for Syria, not partition. The document agreed on Thursday stressed that the federal system would “guarantee the unity of Syrian territory.”

An official in Turkey said: “Syria must remain as one without being weakened and the Syrian people must decide on its future in agreement and with a constitution. Every unilateral initiative will harm Syria’s unity.”

Turkey fears growing Kurdish sway in Syria is fuelling separatism among its own minority Kurds, and considers the main Syrian Kurdish militia to be an ally of the PKK, which has fought an insurgency for Kurdish autonomy in southeast Turkey.