An approach is described for a user equipment (UE) for transmission of hybrid automatic repeat request-acknowledgement (HARQ-ACK) feedback in communication with a next-generation NodeB (gNB) using new radio unlicensed (NR-U) in an unlicensed spectrum. The UE receives downlink (DL) data in a first channel occupancy time (COT). The UE also receives a triggering downlink control indicator (DCI) during a second COT, the triggering DCI providing an indication of a HARQ feedback that is pending for a corresponding HARQ process, and the second COT carrying no scheduled DL data. In addition, the UE receives a triggering downlink control indicator (DCI) during a second COT, the triggering DCI providing an indication of a HARQ feedback that is pending for a corresponding HARQ process, and the second COT carrying no scheduled DL data. The UE transmits the HARQ feedback based on the triggering DCI.