Facing China's growing assertiveness in the Indo-Pacific region, Japan will raise its level of concern about its neighbor's military moves by calling them "the greatest strategic challenge" in an annual foreign policy report, a draft showed Wednesday.

The expression in the Diplomatic Bluebook for 2023, changing from "strong security concerns" in last year's edition, reflects the government's long-term policy guidelines in the recently updated National Security Strategy that used the same wording, according to the draft obtained by Kyodo News.

Beijing's diplomatic stance and military activities have become "a matter of serious concern for Japan and the international community," the draft paper said.

Compiled by the Foreign Ministry, the bluebook is expected to be released around April after approval by the Cabinet of Prime Minister Fumio Kishida.

The policy report mirrors Japan's concern about Beijing's possible use of military force against Taiwan, a self-ruled democratic island that Beijing regards as an inseparable part of China to be eventually reunified with the mainland.

The draft said peace and stability across the Taiwan Strait are important, while calling strengthened military ties between China and Russia a "grave concern" given Moscow's ongoing invasion of Ukraine.

Tokyo will stress that any threats to use nuclear weapons by Russia against its former Soviet neighbor are intolerable, especially to Japan as the only nation to have suffered wartime atomic bombings.

It will also pledge to maintain economic sanctions on Russia while providing support to Ukraine.

In lockstep with other Group of Seven industrialized countries, Japan has been imposing punitive steps against Moscow, such as freezing assets belonging to Russian President Vladimir Putin and the Russian central bank.

But Tokyo will continue to aim for a peace treaty with the Kremlin and settlement of their decades-long dispute over four Russian-occupied islands, called the Northern Territories in Japan and the Southern Kurils in Russia, according to the draft.

On South Korea, the report will refer to Seoul's announcement earlier this month of its solution to a wartime labor issue with Japan as a positive development and call for mending bilateral relations.

Following Seoul's solution proposal to the long-standing row, Kishida and South Korean President Yoon Suk Yeol held a summit in Tokyo last week in a show of increasing momentum for rapprochement.