The option to build two advanced Aegis destroyers to protect Japan from the North Korean missile threat would cost over 500 billion yen ($4.8 billion), more expensive than the scrapped plan to introduce a land-based interception system, sources close to the matter said Tuesday.

The government has been seeking alternatives since its decision earlier this year to scrap the plan to deploy the U.S.-developed Aegis Ashore system in northeastern and western Japan due to technical problems and ballooning costs.

Photo taken March 19, 2020, from a Kyodo News helicopter shows the Japanese Maritime Self-Defense Force's seventh Aegis-equipped destroyer, Maya, which was put into commission after it was handed over to the Defense Ministry at a shipyard in Yokohama, near Tokyo, the same day. (Kyodo) ==Kyodo

The estimate, compiled by two companies commissioned by the government, compares with the 400 billion yen projected for the Aegis Ashore plan, the sources said.

It does not include relevant costs to be incurred for 30 years following the introduction of the ships. If such additional costs are included, the overall cost could expand to around 700 billion yen, according to an earlier projection by the Defense Ministry.

The government will present the latest estimate to a meeting of relevant panels of the ruling Liberal Democratic Party on Wednesday.

The estimate also says it would take at least five years to introduce the two Aegis ships, according to the sources.

The ministry has disclosed three sea-based alternatives for the Aegis Ashore plan, also including remodeling private-sector vessels to accommodate the Aegis system and building dedicated platforms on the sea.

The ministry is aiming to narrow down its options by the end of the year.

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