Merriman said the changes were a "move in the right direction" that would offer "more potential for quarantine-free holidays for UK travellers".
Travel had been anticipating an announcement from UK transport secretary Grant Shapps at around 5pm on Thursday (24 June).
Around an hour later, the Northern Ireland Executive published a list of 16 additions to its green list, including the Balearic Islands, Malta, Madeira and several Caribbean destinations.