Russian Foreign Minister Sergei Lavrov says the US is seeking to use its allies in Syria, especially the Kurds, in order to establish a quasi-state east of the Euphrates River and create illegal structures there.

“On Syrian territory there are vast lands east of the Euphrates where absolutely unacceptable things are taking place,” Lavrov said in a Friday interview with the French website of Russia's state-run RT channel, along with France's Paris Match and Le Figaro.

“The US is trying to use these lands through their Syrian allies – above all, through the Kurds – in order to establish a quasi-state there,” he went on to say.

“But the US is by all means illegally seeking to establish a quasi-state on this territory, trying to do everything there to create conditions for a normal way of living for their subordinates, creating a structure of authority which is an alternative to those legitimate [structures] of the Syrian Arabic Republic,” the top Russian diplomat noted.

Lavrov stressed that the US is encouraging the resettlement of refugees in the territories under their control, undermining the peace process in the country.

“The question is why they, on the eastern bank of the Euphrates River which is controlled by the US and their local allies, do not have to wait until the beginning of a credible political process,” he asked.

He said the US "planned to establish a territory that would be a kind of a prototype of a new state or it will be another round of the most dangerous game with Iraqi Kurdistan, the idea of the so-called unified Kurdistan."

Lavrov regretted that the US is trying to “catch the fish they want” in such “muddy waters”, adding that such kind of strategies "never ended up well".

The Russian minister’s remarks echoed concerns earlier raised by Turkey over US massing of heavy weapons in support of Kurdish militants on the eastern side of the Euphrates.

Turkish President Recep Tayyip Erdogan said recently that "the biggest threat to Syria's future lies in the nests of terror to the east of the Euphrates," citing the Kurdish People's Protection Units (YPG) and the Democratic Union Party (PYD) which are supported by the US.

Lavrov said last month that “the main danger to Syria’s territorial integrity originates from the eastern bank of the Euphrates, where independent and autonomous structures are created under the direct control of the United States.”

A couple of weeks ago, Syrian Foreign Minister Walid al-Muallem also took a swipe at the US for a collapse of talks between the Syrian government and the Kurdish forces who are allegedly encouraged by the US to push for further autonomy.

"The Americans entered Syria without legitimacy and their presence strengthens the Kurds' tendency to secede," Muallem said on September 30.