On 10 November, in regards to U.S. troop levels in Syria, Chairman of the Joint Chiefs of Staff Mark Milley stated that there will be fewer than 1,000 troops remaining "for sure" and estimated that number would be around 500 to 600; Defense Secretary Mark Esper echoed the 600 estimate three days later, adding that numbers could fluctuate depending on the situation on the ground and the possible increase of European presence in the country.