The uninhabited Mageshima island lies about 12 kilometers west of Tanegashima island off the southern coast of Kagoshima Prefecture. (Asahi Shimbun file photo)

The government has finally reached agreement in principle to purchase an uninhabited island in southwestern Japan for use as a training site for U.S. aircraft carrier-based aircraft as well as the Self-Defense Forces.

Several government sources, as well as those with the company that owns a large portion of Mageshima island south of Kagoshima Prefecture, confirmed that a sales agreement was close to completion. The purchase price is about 16 billion yen ($146 million).

The purchase is in line with an agreement reached eight years ago in which Japan promised to provide the U.S. military with a training site after moving landing practice from Iwoto island, once more commonly known as Iwojima, south of Tokyo.

Taston Airport, a Tokyo-based development company, owns 99 percent of Mageshima. In January, the company and the central government reached a tentative agreement on selling the island.

But negotiations hit a roadblock after a new president took over.

In May, the company informed the government that it was breaking off negotiations.

According to sources, individuals with ties to the Defense Ministry informally contacted the company in November. Negotiations moved forward in part because Taston Airport had little choice but to sell the island in light of the financial difficulties it is facing.

The government was also under pressure from Washington to secure land that could be used for landing practice for carrier-based jets.

Under the agreement, Taston Airport will hold on to a sliver of land on the condition that it would also be eventually sold to the government.

Mageshima is about eight square kilometers in size and located about 12 kilometers west of Tanegashima island.

Negotiations were never very smooth after the 2011 agreement was reached with the United States.

The Defense Ministry initially calculated the value of the island at about 4.5 billion yen, but Taston Airport claimed the island was worth 10 times that amount. The new purchase price was apparently reached after taking into consideration the investments made by the company to improve its property on the island.

The government plans to not only have the U.S. military use the island after it is acquired, but to also turn it into a base for the SDF as part of its efforts to shore up defenses in the southwestern chain of islands off Kyushu, especially in light of recent maritime advances by China.

But it still remains to be seen if the U.S. military will be allowed to conduct landing practice on the island because Nishinoomote city, which has jurisdiction over Mageshima and owns the remaining 1 percent of the island, has expressed a cautious stance toward such military training.

(This article was written by Yoshitaka Ito and Ryo Aibara.)