Okinawa is planning to formally invite Universal Studios Japan to open a theme park in the Nago area, a prefectural official said Thursday.

If USJ decides to make Okinawa the site of its second Japan-based theme park, after Osaka, the favored location is a 27-hectare area along Route 58, just east of the Nago city center.

The prefecture will select a site by early next year.

Construction costs are estimated at ¥20 billion to ¥25 billion, and officials hope that the new park will be open by 2018.

Unlike USJ Osaka, which opened in 2001, Okinawa USJ would emphasize the prefecture's marine environment and include an aquarium, a prefectural official said.

"We're drawing up plans to invite USJ and discussing Nago as a candidate site for a new USJ theme park," said Seijun Wakugawa, head of the prefecture's culture, tourism and sports department, during a prefectural assembly meeting Thursday.

One major question is whether a USJ complex in Okinawa would include a casino.

In July, USJ CEO Glenn Gumpel indicated in an interview with the Asahi Shimbun that the company wants to enter the integrated resort sector, which includes casinos, if Japan legalizes gambling.

While USJ Osaka might seem like the natural place to build a casino, Osaka Mayor Toru Hashimoto is opposed to the idea, leaving USJ officials to look at other localities like Okinawa.

Discussions are now underway in the Diet about approving a few locations in Japan for casinos. Okinawa faces competition for a casino license from Osaka, Hokkaido and nearly a half-dozen other prefectures.

In addition, Okinawa hopes that a USJ facility would open before 2019, when both Osaka Gov. Hirokazu Nakaima and Chief Cabinet Secretary Yoshihide Suga have said they want to see U.S. Marine Corps Air Station Futenma, in Ginowan, closed.

A controversial replacement facility in Nago's Henoko district is now being constructed, and the U.S. has said the marines will not leave Futenma until the new base is operational. Opening a USJ theme park in the area before then, Nakaima appears to be thinking, would help dampen local opposition to the Henoko base.

The Okinawa Prefectural Government has predicted that a USJ theme park would draw at least 1.5 million visitors annually and attract tourists from other parts of Japan and East Asia, as well as U.S. military personnel and their families stationed throughout Okinawa.

According to the prefecture, more than 6.4 million tourists visited Okinawa in 2013, a nearly 10 percent increase over 2012. Foreign tourists accounted for about 550,000 of the total, including 235,600 visitors from Taiwan, 84,300 from Hong Kong and 80,000 from South Korea.