Hundreds of trucks carrying US personnel were observed by CNN gathering near Hasakah, Syria, en route east to the border with Iraq.
A US official confirmed the ground move, the largest the US has made in Syria so far, marks the symbolic end of the major US presence in the region.
Secretary of Defense Mark Esper has said the withdrawal would take weeks. Sunday's move from US positions in Kobani, forms a substantial part of the overall withdrawal.
Speaking to reporters Saturday aboard a US military aircraft en route to a refueling stop before heading to Afghanistan, Esper said those troops would be withdrawing via helicopters, fixed wing aircraft, and ground convoys.
Esper said the 1,000 troops are being deployed to two missions, “one is to help defend Iraq and two is to perform a counter-ISIS mission as we sort through the next steps.”
A senior US official later clarified that the location of the 1,000 troops is fluid, indicating it’s possible that not all 1,000 would be relocated to western Iraq. Any relocation out of Syria will be done in conjunction with host country governments, the official added.