Kurdish-controlled areas of northern Syria are expected to  declare a federal system imminently, Kurdish officials said on Wednesday, taking matters into their own hands after being excluded from talks in Geneva to resolve Syria's civil war.

The step aims to combine three Kurdish-led autonomous areas of northern Syrian into a federal arrangement and will be sure to alarm neighbouring Turkey, which fears a growing Kurdish sway in Syria is fuelling separatism among its own minority Kurds.

A conference in the Kurdish-controlled town of Rmeilan on Wednesday was discussing a "Democratic Federal System for Rojava - Northern Syria". Rojava is the Kurdish name for northern Syria.

Conference participants also forecast a failure of U.N.-led talks which began in Geneva this week, in the absence of the Syrian Kurdish PYD party.

Aldar Khalil, a Kurdish official and one of the organisers, told Reuters he anticipated the approval of a new system, and "democratic federalism" was the best one. Idris Nassan, another Kurdish official, expected a declaration of federalism.

Meanwhile, the Syrian Observatory for Human Rights said that Syrian Kurdish internal security forces -- known as the Asayish -- had arrested 60 members of a pro-Syrian government militia in the northeastern city of Qamishli.

It said the Asayish also shelled an area containing government security buildings. Most of Qamishli is held by Kurdish security forces, though the Syrian government retains a presence in the city and controls its airport.

Syrian Kurds effectively control an uninterrupted stretch of 400 km (250 miles) along the Syrian-Turkish border from the Euphrates river to the frontier with Iraq, where Iraqi Kurds have enjoyed autonomy since the early 1990s. They also hold a separate section of the northwestern border in the Afrin area.

Turkey and Iran also both have Kurdish minorities.

 Turkey rejects Kurdish moves

 Turkey, whose conflict with the Kurdish PKK has escalated in recent months, said such moves were not acceptable. "Syria's national unity and territorial integrity is fundamental for us. Outside of this, unilateral decisions cannot have validity," a Turkish Foreign Ministry official told Reuters.

The PYD has been left out of the Geneva peace talks, in line with the wishes of Turkey, which sees it as an extension of the PKK group that is waging an insurgency in southeastern Turkey.

The area of northern Syria controlled by the Syrian Kurdish YPG militia and groups fighting with it is growing with their advances against Islamic State militants over the last year. Their campaign has been backed by U.S.-led air strikes.

On Saturday, Syria's government in Damascus ruled out the idea of a federal system for the country, just days after a Russian official said that could be a possible model.

Syrian Kurdish groups and their allies have already carved out three autonomous zones, or cantons, known as Jazeera, Kobani and Afrin. Their capture of the town of Tel Abyad from Islamic State last year created territorial contiguity between the Jazeera and Kobani areas.

Afrin is separated from the other two cantons by roughly 100 km of territory, much of it still held by Islamic State.

Nassan said a federal arrangement would widen "the framework of self-administration which the Kurds and others have formed", and the political system would represent all ethnic groups living in the area of its authority.

The system envisions "areas of democratic self-administration" that will manage their own economic, security and defence affairs, according to a document drafted by a committee in preparation for the meeting and seen by Reuters. Khalil said details of the system would be worked out later on.