The Syrian Kurdish Democratic Union Party (PYD), which controls most of northern Syria is expected to declare a federal system on Wednesday, a spokesman from the group said. The announcement immediately received a rebuke from the United States.

U.S. State Department deputy spokesman Mark Toner said the U.S. will not recognize any self-rule in Syria. He said: "We have not and will not recognize any self-rule, semi-autonomous zone. We remain committed to the unity and territorial integrity of Syria." U.S. officials repeatedly said they would focus on advancing a negotiated political transition in Syria that will address the parties' demands for autonomous or federal region.

The PYD's step will combine three of its autonomous areas of northern Syrian into a federal region. The announcement would mean "widening the framework of self-administration that the Kurds and others have formed," said Idris Nassan, an official in the Foreign Affairs Directorate of Kobani, one of three autonomous areas set up by the group two years ago. He told Reuters the areas would be called the "Federation of Northern Syria."

The PYD has been left out of peace talks underway in Geneva, in line with pressure from Ankara, which considers it to be the PKK terrorist group's affiliate in Syria.

Syria's regime in Damascus on Saturday ruled out the idea of a federal model for the country, although its ally Russia has said federalism could be a possible model for Syria.

Ankara has repeatedly voiced its concern over the PYD's affiliation with the PKK and the sharing of logistical information and weaponry between them. Prime Minister Ahmet Davutoğlu has repeatedly said that Turkey has no problem with the Kurds in Syria, but the PYD will not be considered a legitimate party or representative of Syrian Kurds due to its relations with the PKK, which is recognized as a terrorist group by the EU and U.S.

While Ankara asserts that the PYD is affiliated with the PKK, Washington does not share Ankara's concern.

The U.S. also provided arms to the PYD in October, which drew heavy criticism from Ankara. The U.S. air force dropped 50 tons of arms and ammunition to the PYD in the northern Syrian province of al-Hasakah. The 112 pallets reportedly contained ammunition for M-16s and AK-47s.

Defending the PYD because it fights DAESH on the ground in Syria, Washington does not agree with Ankara concerning the PYD. Even though the U.S. says the PYD is the only effective force fighting DAESH on the ground, Ankara reiterates that there cannot be any distinction between good and bad terrorist organizations.

State Departman spokesman John Kirby said last month that the U.S. is firmly in favor of a Syria free of any type of sectarianism. "We support a whole, unified, nonsectarian Syria. It's right there in black and white," he said.