 Outside Huế , elements of the U.S. 1st Air Cavalry Division and the 101st Airborne Division fought to seal PAVN access and cut off their lines of supply and reinforcement . By this point in the battle 16 to 18 PAVN battalions ( 8 @,@ 000 @-@ 11 @,@ 000 men ) were taking part in the fighting for the city itself or the approaches to the former imperial capital . Two of the North Vietnamese regiments had made a forced march from the vicinity of Khe Sanh to Huế in order to participate . During most of February , the allies gradually fought their way towards the Citadel , which was only taken after four days of intense struggle . The city was not declared recaptured by U.S. and ARVN forces until 24 February , when members of the 2nd Battalion , 3rd Regiment , 1st ARVN Division raised the South Vietnamese flag over the Palace of Perfect Peace . 
