FAS previously said that around 300 away tickets would only be available for purchase from 3pm to 30 minutes after kick-off of the match.
However, in a social media post on December 24, the association said that away tickets have been allocated through the Vietnam Football Federation (VFF).
The first leg of the semi-final will kick off at the 6,000-seater Jalan Besar Stadium at 9pm on December 26 (local time). All tickets for the game were sold out on December 22, slightly over six hours after sales began.
Similarly, tickets for Vietnam's home game on December 29 at the 20,000-seat Viet Tri Stadium in Phu Tho province were sold out just 15 minutes after online sales opened, also on December 22.
After defeating Myanmar 5-0, Vietnam stand firm in the top spot of Group B and will play Group A second-placed winners Singapore in the semi-finals.
Meanwhile, the Philippines defeat Indonesia 1-0 and will take on Group A winners Thailand in the semi-finals.
