The 2025 World Exposition in Osaka City, western Japan, is scheduled to open one year from Saturday.
Construction of the Grand Roof, also known as the Ring, is underway. The large wooden structure will be one of the centerpieces of the site in the city's Yumeshima district.
More than 50 of the participating countries are considering building their own pavilions, but over ten of them have still not found contractors.
Officials of the Japan Association for the 2025 World Exhibition told NHK that there is a pressing need for the countries to face reality while taking account of budgetary constraints and other factors.
The association has asked these countries to consider using facilities it has prepared.
The association also plans to tackle possible operational challenges such as access to the site.
Public enthusiasm for the expo is reportedly lacking in Japan. In an opinion poll that NHK conducted earlier this month, 31 percent of the respondents expressed interest in the expo, while 63 percent said they are not interested.
The association plans to strengthen its publicity campaign across the country. It is expected to give briefings on why the expo matters, along with details of the exhibitions and scheduled events.
Expo 2025 Osaka, Kansai, Japan is scheduled to run for six months from April 13 through October 13.