Japan is planning to remodel its existing surface-to-air guided missiles so that they can intercept hypersonic glide weapons, which are believed to be under development by countries such as China and Russia, a source familiar with the matter told Kyodo News on Monday.

The government aims to begin mass production of the remodeled Type-03 intermediate-range guided missiles deployed by the Ground Self-Defense Force by fiscal 2029 starting in April that year, after updating their launch software by fiscal 2026, according to the source.

As part of efforts to boost "comprehensive air and missile defense" capability, the government will mention remodeling the missile interceptors in the National Security Strategy, a long-term policy guideline that is expected to be revised by the end of this year, the source said.

File photo shows a Type-03 intermeidate-range surface-to-air missile. (Photo courtesy of Ground Self-Defense Force)(Kyodo)

It is difficult for Japan with its current missile defense capability to intercept hypersonic glide weapons, which are designed to travel at more than five times the speed of sound on irregular trajectories, according to a senior official of the Self-Defense Forces.

Currently, Maritime Self-Defense Force Aegis destroyers equipped with Standard Missile-3 interceptors are tasked with hitting incoming missiles in the outer atmosphere. If they fail to intercept them, the Air Self-Defense Force's ground-based Patriot Advanced Capability-3 interceptors will counter the attack in the lower tier.

The Type-03 missiles with a firing range of tens of kilometers were adopted by the GSDF in 2003 to intercept airplanes. The missiles were first remodeled in 2017 to deal with cruise missiles flying at low altitudes and fast-moving incoming projectiles.

In the planned remodeling, the abilities of the Type-03 missiles will be improved to predict the flight path of hypersonic weapons and track them as well as to detect them by radar, the source added.

But it remains uncertain whether the remodeled missiles will allow Japan to counter hypersonic weapons, the source said, as the race among major military powers to develop hypersonic weapons has been intensifying and technologies are expected to continue to advance.

Japanese Defense Minister Yasukazu Hamada and his U.S. counterpart Lloyd Austin agreed when they met at the Pentagon in September that their nations will undertake joint technological research into hypersonic weapons.

Facing growing security challenges such as China's military buildup, North Korea's repeated ballistic missile launches and Russia's prolonged war in Ukraine, Prime Minister Fumio Kishida has vowed to "fundamentally" boost defense capabilities with a substantially increased defense budget.