With increasing military action from China in the East China Sea, the defense ministers of Japan and the Philippines agreed Thursday to bolster security cooperation and expand joint drills between their forces.

Japanese Defense Minister Nobuo Kishi and his Philippine counterpart, Delfin Lorenzana, also shared concern about Russia's invasion of Ukraine and its impact on the Indo-Pacific and noted that any attempts to change the status quo by force are unacceptable, Japan's Defense Ministry said in a statement that avoided identifying China by name.

Japan has significantly expanded joint drills with the United States and other partners, including Australia, India, France, Britain and Germany, that share its concerns about China's assertion of its territorial claims in the region, which has some of the world's busiest sea lanes.

Japan is especially concerned about Chinese military and coast guard activity in the East China Sea near the Japanese-controlled Senkaku islands, which China also claims and calls Diaoyu.

On Thursday, Japan's Defense Ministry said it spotted a Chinese Y-9 electronic warfare aircraft flying over the Sakishima islands, although it did not violate Japanese airspace.

Kishi and Lorenzana also agreed to increase cooperation in defense equipment and technology transfer between the two countries. Tokyo and Manila agreed in 2020 on the Japanese export of air radar systems to the Philippine military.

For Japan, the Philippines is geopolitically important as China increases its influence in the region. China, the Philippines, Vietnam, Taiwan, Malaysia and Brunei have been locked in an increasingly tense territorial standoff in the busy waterway for decades.

The defense ministers will be joined by foreign ministers from each country on Saturday for the first "two plus two" security talks between the two countries.