There is no evidence of increased US troops being deployed in Syria, and Biden has not sent more U.S. troops to Syria.
The claim relied on a report by the Syrian state news agency SANA. It said a large U.S. military convoy entered northeastern Syria from Iraq, citing sources on the ground. SANA also reports that some 200 US troops arrived in the Hasakeh province on helicopters.
U.S. troops have been stationed in Syria as part of coalition forces to support the Kurdish-led Syrian Democratic Forces (SDF) to fight against ISIS. In late 2020, then-U.S. President Donald Trump had ordered U.S. troops to withdraw from the area and redeploy to Iraq.
Local media has reported that the U.S. often moves its troops and equipment between Iraq and Syria, a normal routine. For now, there is no evidence of an increased U.S. military presence or mobilization in the region, a change in posture in the Syrian region. Biden has yet to disclose his policy on the Syrian issue. The claim seems to be a conspiracy theory being spread online as the situation is completely misread.
Further, there are no reports from the White House of any additional U.S. troops being sent to Syria. Thus we can conclude that the claims about Biden sending additional U.S. troops to Syria are baseless and cannot be corroborated with facts.