The Islamic State forces north of the Euphrates are left to holding some 4 square kilometer of ground near the border to Iraq. The few hundred ISIS fighters still alive could be killed in a day or two which would then be the right time for the U.S. to leave as President Trump announced two month ago.

But the U.S. military keeps increasing its troop numbers and supplies in the area. During the last two month the number of U.S. soldiers in northeast Syria rose by nearly 50%. Instead of the officially acknowledged 2,000 there are now at least 3,000 U.S. soldiers in northeast Syria. New weapons and equipment arrive every day. Additionally, the Syrian Observatory reports, the U.S. is bringing in a significant number of TOW anti-tank missiles and heavy machine guns even though there is no longer an apparent use for these:

[T]he International Coalition Forces brought quantities of anti-armor thermal missiles during the recent period, to their bases east of Euphrates area, in conjunction with bringing quantities of machineguns known as "DShK", and the reliable sources confirmed to the Syrian Observatory that the range of the missiles reaches about 6 km, but the reasons for bringing these weapons was not known, especially as the "Islamic State" Organization in its last pocket at the east bank of Euphrates River is almost ended, ..
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[T]he Syrian Observatory has documented since the US president's decision to withdraw until the 3rd of February 2018, the entry of 1130 trucks at least, carrying equipment, ammunition, weapons, military, and logistic equipment to bases of the International Coalition east of Euphrates, ..