Strengthening the U.S.-Japan alliance is more important than ever for Japan’s national security as challenges with China, cybersecurity and elsewhere continue to evolve, according to new defense guidelines approved Tuesday by the Cabinet.

The “severity and uncertainty” of these challenges “is increasing with extremely high speed,” said the National Defense Program Guideline, which sets guidance for Japan’s defense strategy.

This is the second guideline revision under Prime Minister Shinzo Abe since 2013.

To counter increased military operations by China near East China Sea islands claimed by both nations, the guideline also supports converting an Izumo-class flat-top helicopter destroyer to accommodate F-35B stealth fighters. Japan plans to acquire 42 of the short takeoff and vertical-landing aircraft in the next 10 years.

The guideline calls for turning the self-defense forces’ attention to threats posed to the nation’s cybersecurity and from space. It also re-emphasizes the U.S.-Japan alliance as vital to Japan’s national security.

“To further strengthen relations with the U.S., which shares the same universal values and strategic interests with our country, has become important more than ever for our national security,” the guideline stated.

Japan will actively support U.S. military operations, such as defending U.S. ships and aircraft, according to the guideline. For example, a recent change to Japanese law allows its self-defense forces to provide logistical support to U.S. forces.

Japan needs to quickly build a new defense capability that promotes the integration of conventional ground, sea and air defenses with new areas of space and cyber, according to the revised guideline.

“Rapid expansion of new areas, such as space, cyber and electromagnetic waves, is fundamentally changing the ideal state of national security, which had placed importance on dealing with physical areas such as land, sea and air,” it stated.

The guideline also calls for all three self-defense forces to jointly address cyber defense and for the Japan Air Self-Defense Force to deal specifically with space.

Converting the Izumo carrier to handle F-35Bs will extend the self-defense forces’ operational reach, defense officials said.

The only Japanese air bases — Naha Air Base and the Maritime Self-Defense Force base on Iwo Jima — have runways of 7,800 feet or longer, where conventional fighters can land. There has been frequent foreign military activity in the East China Sea and western Pacific Ocean, government officials said.

Operational flexibility will increase if short-takeoff, vertical-landing capable aircraft could operate from an Izumo-class platform when conducting air-defense operations in remote areas, the official said.

Critics say reworking the helicopter destroyers will give Japan strike capability, a violation of its pacifist constitution.

However, officials say the converted helicopter destroyer will not be used solely as a full-fledged aircraft carrier like those in the U.S. Navy. It will continue to operate as a multifunctional destroyer, playing a central role in anti-submarine warfare missions and disaster-relief operations.

The Cabinet on Tuesday also endorsed a plan to introduce 147 F-35s, and called for streamlining the self-defense forces, citing the country’s declining workforce and population and its struggling economy.

The Cabinet also approved the Mid-Term Defense Program, which specifies equipment to be acquired over the next five years. It said total spending will be a record $240 billion, which is about $17.8 billion more than in an earlier defense budget, according to The Associated Press.