Francesco Friangelli, secretary-general of the tourism industry body, told a regional meeting in Manila that the four Middle Eastern countries, along with Bhutan and Bermuda, had "indicated their desire to join or rejoin" the organization.
He said it might seem unusual that oil-rich countries "with no problems with balance of payments" would be turning to tourism.
But these moves showed that these countries were "thinking in the long-term," in creating new jobs for their nationals and trying to diversify their economies which are dependent on oil exports.
Friangelli said he was expecting word soon that Oman was also willing, adding that even Libya and Iran were now preparing tourism master plans.
Because of the expected entry of so many Arab countries, the organization was "now in the position to introduce the Arabic language" in its operations.
He also said that the organization was maintaining close ties with the Arab League and the Organization of Islamic Conference to smoothen the entry of these largely-Islamic countries.
The World Tourism Organization, which is made up of over 140 countries, is seeking special status with the United Nations, similar to the International Labour Organization and the Food and Agricultural Organization.