BEIRUT -- Russia, Turkey and the Syrian government on Monday denounced the U.S.-led coalition plans to form a Kurdish-led border force to secure the areas along Syria's international border to the north with Turkey and to the east, with Iraq.

The coalition told The Associated Press Monday that 230 new cadets have already been recruited to the force, which is anticipated to reach 30,000 troops in the next several years.

According to the coalition, the core of the force is to be made up of fighters from the existing Kurdish-led Syrian Democratic Forces, the coalition's main ally in the fight against Islamic State of Iraq and Syria (ISIS) militants. The SDF currently controls nearly 25 percent of Syrian territory in the north and east.

"A strong border security force will prohibit (ISIS) freedom of movement and deny the transportation of illicit materials," the coalition said in a statement." This will enable the Syrian people to establish effective local, representative governance and reclaim their land."

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Turkey has already protested the new force, which adds another bump in the troubled relations between Washington and Ankara over Syria.

On Monday, Turkish Deputy Prime Minister Bekir Bozdag said the United States is building "a terrorist army under the guise of the Syrian Border Security force." Bozdag also tweeted that Washington is "playing with fire."

Turkey has been against U.S. support of the dominant Kurdish militia in Syria, which forms the backbone of the SDF, calling it an extension of its own insurgent group. Ankara sent troops into Syria in 2016 to prevent Syrian Kurdish fighters from forming a contiguous entity along its border. It has also supported rival Syrian rebels and independently took part in the effort to clear ISIS militants from Syria, where the terrain has been crowded with rival and often competing forces.

Russian Foreign Minister Sergey Lavrov said the new force is a sign Washington "doesn't want to preserve the territorial integrity of Syria." Lavrov said the nascent border force is "not helping calm the situation" and suggested it would only increase tensions.

Turkey has announced it will soon launch a new operation to take the northwestern Syrian town of Afrin, sending reinforcements to the borders. President Recep Tayyip Erdogan said the operation against Afrin is to "purge terror" from Turkey's southern border and called on the U.S. to support its efforts.

Russia sent military observers to Afrin last year in an effort to prevent an outbreak of Turkish-Kurdish tensions.

Russian President Vladimir Putin (C), Turkish President Recep Tayyip Erdogan (R) and Iranian President Hassan Rouhani pose during a trilateral meeting on Syria in Sochi on November 22, 2017. Getty

Moscow, a main backer of Syrian President Bashar Assad, and Ankara have supported opposite sides in the conflict, but they struck a deal last year to set up de-escalation zones. The agreement, which also included Assad-backer Iran, has helped reduce fighting significantly and contributed to warmer ties between Russia and Turkey. Turkey's warming up to Moscow is in part due to souring relations with Washington over its support of the Kurdish militia.

For its part, Assad's government on Monday also condemned the U.S. plans for the border force, calling it "a blatant encroachment upon the sovereignty, unity and territorial integrity of Syria" and a violation of international law.