Papua New Guinea's Tourism Promotion Authority says the national airline, Air Niugini, must improve its services.
The authority is joining into criticism by the tourism minister who says the airline is an impediment to the country's tourism development.
Air Niugini operates a domestic network from Port Moresby and Lae, as well as an international service to Australia and Asian destinations.
The chief executive officer of the tourism body, Peter Vincent, says the airline causes massive problems for his sector.
"PNG happens to be the biggest Pacific Island country with an immense economic potential for development and the airline plays an important role. Unfortunately we can't say that for Air Niugini at this point in time. The private sector members of the tourism industry raised the issue with Air Niugini, complaining about the level of service and unreliability and the delays we experience in the tourism sector in PNG."
Peter Vincent says he believes competition would help alleviate the problem.