China put 20 more Japanese organizations on a blacklist Monday over the export of items with both military and civilian possible uses, adding fuel to a months-long row with Tokyo.
The new additions, including major companies, "have participated in enhancing Japan's military capabilities", the Chinese commerce ministry said in a statement.
Japan's government spokesman Minoru Kihara called the measures "unacceptable and deeply regrettable" and said Tokyo had "lodged a strong protest and demanded that the measures be withdrawn."
The countries' have been at row since Japanese Prime Minister Sanae Takaichi suggested in November that Tokyo may react militarily to an attack on Taiwan, the self-ruled island Beijing has vowed to seize control by force if necessary.
China responded furiously, including by advising its citizens -- previously the biggest cohort of foreign tourists -- to avoid Japan.
Chinese authorities ramped up pressure in February by imposing export restrictions on dozens of Japanese firms it said were involved in building up Tokyo's military.
The 20 additions to the export blacklist named Monday include specialized subsidiaries and technology firms involved in supplying components and engineering support for Japan's defense sector.
Among them are the National Institute for Defense Studies and Mitsubishi Electric Defense and Space Technologies Corporation, the statement said.
China's commerce ministry said the controls require exporters to submit risk assessments and guarantees that dual-use items will not enhance Japanese military strength prior to making shipments.
Those named on the watchlist can apply to be removed by cooperating with "verification" procedures according to Chinese law, the ministry said.
China is the world's largest producer and refiner of rare earths, which are crucial for various high-tech products including electric vehicles, smartphones, missile guidance systems and lasers.
Japan has "strayed further down the wrong path, intensifying its push for a 'new form of militarism'", an unnamed commerce ministry spokesperson said in a statement on the latest measures.
- China-Russia patrols -
Since Takaichi took office in October, Japan has quickened its pivot towards a more proactive defense policy, further shaking off -- with US encouragement -- a pacifist outlook, which has been in place since the end of World War II.
Tokyo has loosened rules on exports of lethal weaponry and deepened military cooperation with other countries in the region at odds with China including the Philippines.
Japan and the United States, as well as many other countries, are seeking to curb dependence on China in rare earths, as Beijing increasingly uses its dominance for geopolitical leverage.
Japan on Monday also joined South Korea in criticizing joint flights by Chinese and Russian bombers and fighters over the weekend in the region.
Fellow US allies South Korea and Japan both scrambled fighter jets in response to the patrols by the convoy of around 15 aircraft on Saturday.
"This marks the 10th instance of such long-range activities by Chinese and Russian bombers in the vicinity of Japan since December last year," Japanese government spokesman Kihara said Monday.
Beijing's defense ministry said that the Chinese and Russian air forces conducted a "strategic air patrol" over the Sea of Japan, the East China Sea and the western Pacific Ocean, "demonstrating their determination and capability to jointly uphold regional peace and stability".
Tokyo last week also rejected Beijing's accusations that the Japanese military "harassed" a Chinese aircraft carrier strike group during 40 days of exercises in the Pacific.
