The measures will effectively mirror those rolled out in Scotland on Friday (15 January), which require arrivals by air, sea and rail to return a negative Covid test result up to 72 hours prior to departure.
England had been due to introduce like measures on Friday, but the rollout was later pushed back to Monday. Northern Ireland is preparing to enact similar rules.
Like England, the Welsh pre-departure testing regime will operate alongside quarantine, rather than replacing it.
