Weerasak said he took UNWTO secretary general Zurab Pololikashvili on a tour of the coastal provinces that would be involved and he expressed interest in the scheme.
The idea is to develop a 220-kilometre stretch of the Gulf coast with international-standard tourist attractions and build double-track railway linking them.
New marine tourism routes to the area would be established. Hua Hin Airport has opened to international flights as part of the project.
Weerasak said the UNWTO would help out by holding a tourism investment forum in one of the Gulf provinces this year, during which member-nations can view the area.
Pololikashvili asked about city planning in the coastal provinces, areas that are designated by law for commercial development, areas that would be secure during monsoon storms, and transportation infrastructure plans.
The information will be passed on to member-nations invited to invest in the Thai Riviera, Weerasak said.