The document includes a chapter on Russia's invasion of Ukraine, which it says risks sending the message "that an attempt to unilaterally change the status quo by force is acceptable".

The paper surveys the global security landscape and specific threats to Japan, and says there was concern Russia could "further enhance and deepen relationships with China".

It also warns Moscow may increasingly lean on its nuclear capacity as a deterrent, which could mean an uptick in activity around Japan, where Russian nuclear submarines are routinely active.

Japan has backed sanctions led by the United States and the European Union against Moscow, and has seen increased Russian military activity around its territory.

In May, Chinese and Russian military jets carried out joint flights near Japan immediately after a meeting of the US-led Quad grouping in Tokyo.

The defence paper also devotes significant space to Taiwan.

It includes the most detailed overview yet of the security situation on the island and notes "since Russia's invasion of Ukraine, Taiwan has been working on further strengthening its self-defence efforts".

Taipei on Friday noted the "great importance" Japan had attached to the island in the report.

"At a time when authoritarianism is expanding and challenging the international order, the Ministry of Foreign Affairs looks forward to working with like-minded countries including Japan to continue to defend universal values and jointly promote stability in the Taiwan Strait as well as freedom, openness, peace and stability in the Indo-Pacific region," the ministry said.

This year's paper was released amid growing expectations that Japan will significantly boost defence spending.

While the defence budget has been rising for years, Japan still has the lowest ratio of military expenditure to Gross Domestic Product (GDP) among Group of Seven countries.

Kishida has publicly backed boosting spending, and his ruling party has a long-term goal of a defence budget equal to two percent of GDP, though experts say it may be difficult to reach that figure quickly.

Japan's military is not officially recognised under the country's post-war constitution and spending is limited to funding nominally defensive capabilities.

The report continues to describe China as a "strong security concern", adding that the risk posed by Beijing "is intensifying in recent years".

It similarly repeats that North Korea poses continued "grave and imminent threats", which it said were also "intensifying".