On 17 May 2021 Announcement by The Government of Taiwan was released, the statment read:
The Central Epidemic Command Center (CECC) announced that entry to Taiwan will be suspended from 00:00 on May 19 (local time of departure) to June 18 for foreign nationals not holding a valid R.O.C. (Taiwan) Resident Certificate. Exceptions will be considered on a case-by-case basis for emergencies and on humanitarian grounds.
For more information, please visit the Taiwan MOFA website.