South Korea has become the first foreign country to submit a basic plan for building its own pavilion at the 2025 World Exposition in western Japan, a source familiar with the matter said Saturday, amid concerns about the slow progress being made by overseas participants concerning preparations for the event.

It is expected some 50 countries will build their own pavilions for the expo, to be held in Osaka, but the city had not received a basic design plan from any participating country, a requirement before seeking construction permission, until it received South Korea's on Friday.

The ability of participating countries to design and build their own pavilions is supposed to be one of the event's key attractions, but a shortage of construction workers and the prospect of various unique designs and installations have made domestic construction companies reluctant to sign contracts.

Supplied illustration shows the design of the venue for the 2025 World Exposition in Osaka. (Courtesy of the Japan Association for the 2025 World Exposition)(Kyodo)

It takes about two months for the event's authorities to grant construction permission for a design after the basic plan is submitted.

In addition to "self-built" pavilions, known as Type A, participants also have the option of renting pavilions made by the event's organizer or sharing an area inside an organizer-made pavilion with others.

Under the current plan, participating countries are supposed to complete the bulk of the construction for their Type A pavilions by July 2024, finalize work on their interiors by January next year and have their planned exhibits completed later in March.

The expo begins on April 13, 2025, but concerns are growing that the pavilions for overseas participants may not be built in time for the opening.

The event will run until Oct. 13 on Yumeshima, an artificial island in Osaka Bay, centered on the theme of "Designing Future Society for Our Lives."

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