Five hundred SDF fighters[28] and additional US soldiers[14] of the CJTF–OIR were airlifted by US V-22 Osprey helicopters across the Euphrates river and Lake Assad[28] and were dropped on the Shurfa Peninsula to the west of Tabqa city.

[31] The airlift of forces behind enemy lines was described by Pentagon spokesman Eric Pahon as a large high-priority offensive and announced that the advance had cut off the highway linking the Aleppo, Deir ez-Zor, and Raqqa Governorates.

[33][34] On 24 March, SDF spokeswoman Jihan Sheikh Ahmed announced that they had reached the Tabqa Dam and were fighting ISIL at its entrance.

[41] The SDF however denied that it had been hit, while the RBSS (Raqqa Is Being Slaughtered Silently) group stated that ISIL was informing fleeing civilians that the dam was safe.

[50][51][52] Later in the day, a spokeswoman of the SDF announced that engineers who had been permitted to check the dam and its operations did not find it was damaged or malfunctioning.

The SDF stated that ISIL had shelled the Tabqa Dam during the day, causing repair work to be temporarily paused.

[61][62] Meanwhile, on 3 April, it was reported that ISIL was possibly in the process of moving its capital from Raqqa city to Mayadin, in the Deir ez-Zor Governorate.

[65][66] The SDF captured Ibad village, located east of Safsafah, on 9 April, further expanding their control in the eastern countryside of Tabqa, while more than 25 ISIL fighters were killed in the clashes.

[72][73] On 13 April, the US military stated that CJTF-OIR had bombed an SDF fighting position near Tabqa as it was misidentified as belonging to ISIL.

[78] On the same day, it was announced that 200 fighters from the Manbij Military Council would participate in this part of the battle, resulting in a total of 350 personnel.

[84] The next day the SDF stated that it had completely captured the Old City, leaving ISIL in control of only the newer areas of the town, alongside the dam.

[85] On 2 May, the SDF stated that it had captured about 90% of the city[86] amid reports of negotiations between Kurdish fighters and ISIL to allow the latter to withdraw from the remaining areas under its control.

[89][91] The SDF and its commanders however denied any deal had been reached, adding that clashes were still ongoing against ISIL in a village near Tabqa and the three northern districts of the town, including some militants who were hiding among civilians.

On one side, 14 Chechen and French African ISIL fighters, members of an elite "ingimassayeen" unit, still held the control room, the floodgates, and a number of tunnels inside Tabqa Dam.

Even though they were left without light or fresh air, as the SDF had shut down all electricity to the dam, and without means to communicate with their allies due to the coalition jamming their radio frequencies, these ISIL fighters had resisted attempts to clear them out for weeks.

The second, bigger holdout was in northern Tabqa city, where around 50 ISIL militants still defended a number of highly fortified apartments.

According to United States Central Command, the Islamists had acceded to the SDF's demand of dismantling the IEDs surrounding the dam.