Japan's Prime Minister Fumio Kishida said Thursday he had expressed "serious concerns" over regional security issues to Chinese President Xi Jinping in Bangkok at the pair's first in-person talks.
The two major economies are key trading partners, but relations have soured as Beijing bolsters its military, projects power regionally, and takes a harder line on territorial rivalries.
Kishida said he had "expressed serious concerns over the situation in the East China Sea, including the Senkaku Islands", referring to Tokyo-controlled disputed islets that Beijing calls the Diaoyus.
He said he also raised concerns over "China's military activities, including ballistic missile launches from China".
In August, Chinese missiles fired during massive military drills around Taiwan are believed to have fallen within Japan's exclusive economic zone.
"I stressed the importance of peace and stability of the Taiwan Strait," Kishida said, adding that the countries had "agreed on strengthening communication in the field of security".
Kishida spoke to Xi on the phone in October 2021 after being elected prime minister, but this is their first in-person meeting.
Xi last held face-to-face talks with a Japanese prime minister in December 2019, when he met Shinzo Abe in Beijing.
China and Japan marked 50 years of diplomatic relations in September, but there was little celebration of the anniversary, given the neighbours' frosty ties.
On Thursday, Kishida said he had "reiterated Japan's position on human rights and detention of Japanese citizens in China" to Xi.
Just hours before the meeting on the sidelines of a summit of the Asia-Pacific Economic Cooperation (APEC) forum, North Korea fired a short-range ballistic missile -- the latest in a record blitz of test launches.
"On North Korea, I expressed our expectation that China will play a role including in the UN security council, and confirmed that I will closely cooperate with state leader Xi," Kishida said.
The pair will work towards "an immediate resolution of the abduction issue", he added, referring to Pyongyang's abductions of Japanese citizens during the Cold War.
Both sides agreed to arrange a visit to China by Japanese Foreign Minister Yoshimasa Hayashi, Kishida said.
Regarding the war in Ukraine, the pair agreed that Russia's hints about the use of nuclear weapons were "concerning" and that "nuclear weapons can never be used and nuclear war can never happen", he added.