The announcement came in the wake of a state of emergency imposed by the Thai government, effective from yesterday (Mar 26) to April 30.
The national governing body for football also announced revised match schedules for all four tiers of domestic leagues.
The FAT and Thai League Co halted all games at the beginning of this month until April 18 when the coronavirus situation started worsening in the country.
A number of leading Thai League 1 clubs had refused to play behind closed doors.
The FAT said it is worried about the health of the players, staff coaches and other team and match officials.
It added in a statement that the fresh delay was necessitated by the state of emergency in the country.
The association expressed confidence that the FA Cup and the League Cup tournaments will take place as scheduled.
The top-flight hostilities are now slated to end on Oct 24 with second-tier Thai League 2 concluding a day later.
The FAT and Thai League Co did not rule out a further delay to the resumption of leagues, saying they would continue monitoring the COVID-19 situation in the Kingdom.
At the same time, the FAT is also trying to gauge the losses the Thai clubs could suffer because of the coronavirus-induced postponements.
Football leagues around the world have come to a halt because of the pandemic and a number of high-profile sporting events, including the 2020 Olympics, have been postponed.