MOSCOW -- The United States' actions in Syria indicate that Washington might be seeking to undermine Syria's territorial integrity, Russian Foreign Minister Sergei Lavrov said Tuesday.

"The Americans, in my opinion, are taking dangerous unilateral steps, which by the way, look more and more like a part of a plan to create a quasi-state on a large part of the Syrian territory, on the eastern bank of the Euphrates and up to the Iraqi border," Lavrov said at a press conference.

He added that he suspected the United States was planning to stay in Syria "for a long time, if not forever."

The United States had claimed that the only purpose of its military presence in Syria was the struggle against the Islamic State (IS) terrorists, Lavrov said, adding but after their defeat, it says that the presence should be retained until the start of a stable political process ending with a transition of power, or an advent of a new regime acceptable to the United States.

Lavrov recalled that the United States attempted to create in Syria institutions outside the control of Damascus.

"Funds are being sent there to ensure that these authorities function and law enforcement bodies, created there with the help of the Americans, are equipped with weapons," he said.

Lavrov said that he hoped that after the start of the constitutional process in Syria, the United Nations would be able to ensure its transparency and to keep all interested members of the international community informed.

In the past several years, the United States has supported some opposition groups in Syria which it called "moderates" against the Syrian government and also led an international coalition to battle the IS group.

However, Damascus considers the US operations in Syria illegal, saying Washington was aiding "terrorists" against the legitimate government of the Middle East country.