Tokyo, Dec 19 (IANS): Japan on Tuesday approved the incorporation of two land-based missile interceptors due to North Korea's growing military clout, the Defence Ministry said.

The government authorised the purchase of two units of the US-made Aegis Ashore for its ground forces, a ministry spokesman told Efe news.

Japan already has Aegis systems installed in several destroyers of its Maritime Self-Defence Forces.

In order to streamline the deployment of these systems, which are expected to be ready "as soon as possible", the ministry has planned to allocate a part of the supplementary budget for this year and increase by 730 million yen ($6.49 million) its record budget of 5.26 billion yen requested for 2018.

On Friday, the Japanese government is expected to approve a draft of the general budget for the country for next year.

It remains to be decided where they will deploy the two anti-missile units, through which Japan seeks to cover the security of its entire territory, where until now the only land-based missile defence system deployed was the Patriot Advanced Capability 3 (PAC-3).

The last units of the PAC-3 were deployed in Hokkaido Island in September, in response to two North Korean missiles that flew over the region - one in the same month and another at the end of August - before falling into the ocean.

Although the Japanese Constitution establishes that Japan can only have defensive military capabilities, the conservative government under Abe has pushed for its reinterpretation in order to bolster its defences.

Since Prime Minister Shinzo Abe came to power around the end of 2012, Japan's defence budget has increased annually in a sustained manner over constant tensions in the Korean peninsula, North Korea's widening defence arsenal and territorial disputes with China.