BEIRUT — Syrian Kurds are preparing a plan to declare a federal region in the area they control across northern Syria, saying Wednesday it is a model for a more decentralized government in which all ethnic groups would be represented.

Although the idea might seem like a way forward after five years of civil war, it faces big obstacles: It was promptly dismissed by the government of Syrian President Bashar Assad and the rebels who oppose him, both fearing it would lead to a partition of the country.

Turkey also opposes it, wary of the growing Kurdish influence in the border region of northern Syria and its effect on its own Kurdish minority.

But Ahmad Araj, a Kurdish official in northern Syria, insisted that a federal system containing such a region, which would effectively combine three Kurdish-led autonomous areas, is meant to preserve national unity and prevent Syria from breaking up along sectarian lines.

“After all the blood that has been spilled, Syrians will not accept anything less than decentralization,” Araj said.

By making the announcement as U.N.-sponsored peace negotiations take place in Geneva, Syria's main Kurdish faction was trying to become a major player in whatever central government emerges from the war. The faction has been excluded from the talks.

The idea of a federal region appears to have gained some traction lately as world and regional powers grapple with ways to end the conflict. Russian Foreign Minister Sergey Lavrov this week said such a federal system is one possible option if the Syrian people agree to it. The U.S. also has been an ardent supporter of the Kurds in the region, helping them in navigating the delicate rivalries in Iraq after the 2003 invasion that toppled Saddam Hussein.

State Department spokesman Mark Toner told reporters that the U.S. opposes declarations of autonomous federal zones prior to a negotiated political resolution in Syria.

“We're focused on advancing a negotiated political transition toward an inclusive government that is capable of serving the interests of all the Syrian people,” Toner said. “We've also been very clear that we're committed to the unity and territorial integrity of Syria.”

However, if a resolution is reached by the Syrian people and their representative, and if it includes a federal system that allows for limited or semi-autonomy for different regions, Toner said Washington would not oppose it.

The Kurdish declaration is expected to be made at the end of a conference that began Wednesday in the town of Rmeilan, in Syria's northern Hassakeh province, and may last several days.

The plan could make sense in a country that has a multitude of sectarian and ethnic minorities for whom it would be difficult to share a unifying national sentiment.

The government, dominated by Assad's Alawite sect of Shiite Islam, controls Damascus, the Alawite heartland along the Mediterranean coast, and other cities and connecting corridors in between. The Kurds run their own affairs in the northeast.

The militants of the Islamic State group control much of the Sunni heartland in the east.

Other Sunni rebels control pockets in the north and south. The Druze remain loyal but are starting to talk about autonomy in their southern areas as well.

Any move to carve up the country could risk more violence, including ethnic or sectarian cleansing.

Joshua Landis, director of Middle East studies at the University of Oklahoma, said the federalist project has logic to it, but is doomed to fail under current conditions.

“The federal system would be the way forward if people would accept it,” Landis said, “But they won't because they don't like each other.”

Kurds are the largest ethnic minority in Syria.